Probing disorder and dynamics in composite electrolytes of an organic ionic plastic crystal and lithium functionalised acrylic polymer nanoparticles

Jou nal o Magne ic Resonance Open 14-15 (2023) 100095 A ailable online 20 Janua y 2023 2666-4410/© 2023 Published by Else ie Inc. This is an open access a icle unde he CC BY-NC-ND license (h p://c ea i ecommons.o g/licenses/by-nc-nd/4.0/). P obing diso de and dynamics in composi e elec oly es o an o ganic ionic plas ic c ys al and li hium unc ionalised ac ylic polyme nanopa icles Yady Ga cía a , * , Luca Po ca elli a , b , Haijin Zhu a , Ma ia Fo sy h a , b , c , Da id Mece eyes b , c , Luke A. O’Dell a a Ins i u e o F on ie Ma e ials and he ARC Cen e o Excellence o Elec oma e ials Science, Deakin Uni e si y, Geelong, VIC 3216, Aus alia b POLYMAT Uni e si y o he Basque Coun y UPV/EHU, Joxe Ma i Ko a Cen e , Donos ia−San Sebas ian 20018, Spain c Ike basque, Basque Founda ion o Science, Bilbao, Spain ARTICLE INFO Keywo ds: Composi e elec oly e Plas ic c ys al Dynamics Li ion mobili y ABSTRACT Solid composi e elec oly es combining an ionic molecula phase o acili a e ion anspo wi h a polyme ic componen o p o ide mechanical s eng h a e p omising ma e ial o solid-s a e ba e ies. Howe e , he s uc u e-p ope y ela ionships o hese complex composi es a e no ully unde s ood. He ein we s udy com- posi es combining he non- lammabili y and he mal s abili y o he o ganic ionic plas ic c ys al (OIPC) N- me hyl-N-e hylpy olidinium bis( i luo ome hanesul onyl) amide [C 2 mpy ][TFSI] wi h he mechanical s eng h o ac ylic polyme nanopa icles unc ionalised wi h sulphonamide g oups ha ing li hium coun e -ca ions. The e ec o he o ma ion o in e aces and in e acial egions be ween he OIPC and polyme nanopa icle on he he mal s abili y, ion anspo , mo phology and ion dynamics we e s udied. I was ound ha he composi es whe e an in e phase was o med by local mixing o he polyme wi h he OIPC upon hea ing showed highe local diso de in he OIPC phase and enhanced ion anspo in compa ison wi h he as-p epa ed composi es. In addi ion, doping he composi e wi h LiTFSI sal led o u he s uc u al diso de in he OIPC and a selec i e inc ease in li hium-ion mobili y. Such an imp o ed undamen al unde s anding o s uc u e, dynamics and in e acial egions in solid elec oly e composi es can in o m he design o OIPC-polyme nanopa icle com- posi es wi h enhanced p ope ies o applica ion as solid elec oly e in ba e ies. 1. In oduc ion The componen s o ene gy-s o age de ices, such as he elec oly e and elec odes, in e ac ia in e aces and in e phases, which play a key ole in egula ing he anspo o ma e and cha ge, and can de e mine he ex insic ac i i y, s abili y and unc ionali y o a de ice [1,2]. Fo example, composi e elec odes may con ain an ac i e ma e ial, poly- me ic binde s ha p o ide mechanical s abili y and conduc i e diluen s such as ca bon black, o acili a e cha ge anspo o he ac i e ma e ial [3], while he o ma ion o he solid elec oly e in e phase (SEI) laye plays a key ole in passi a ing he elec ode su ace. Whe e possible, i is desi able o design in e aces and in e phases wi h speci ic p ope ies such as enhanced ion anspo ha can con ibu e o he imp o ed unc ionali y and eliabili y o he de ice [4]. He e we de ine an in e - ace o be he poin a which wo di e en componen s mee , and an in e phase o be a egion dis inc om he pu e componen s hemsel es (e.g. a egion wi h enhanced s uc u al diso de o dynamics, o whe e he componen s ha e mixed oge he ). Impo an ad ances owa ds sa e ope a ional de ices ha e been achie ed h ough solid-s a e elec- oly es. Thei inhe en mechanisms, such as hei low di usion o ma e , allow o con ol o e he in e phase g ow h and o s abiliza- ion o he elec odes (e.g. Li me al) [1,5]. Solid-s a e elec oly es can be ino ganic (pe o ski e, ga ne , sulphide- ype ma e ials, e c.) o o ganic (ionic plas ic c ys als (OIPCs), polyme s and composi e sys ems) and ypically exhibi ionic conduc i i ies up o a ound he o de o 10 −3 S cm −1 a oom empe a u e [6]. Composi e solid elec oly es a e a e y p omising app oach as hey can combine he ad an ageous p ope ies o hei componen s [7,8]. Fo example, composi es be ween OIPCs and polyme nanopa icles ha e ecen ly been de eloped ha combine he ionic conduc i i y, non- lammabili y, non- ola ili y, plas ici y, elec ochemical, and he - mal s abili y o OIPCs, while a he same ime o e ing he mechanical s abili y (and po en ially also chemical unc ionali y) p o ided by he polyme [9,10]. In hese elec oly e ma e ials he o ma ion o in e aces * Co esponding au ho . E-mail add esses: [email p o ec ed] (Y. Ga cía), [email p o ec ed] (L.A. O’Dell). Con en s lis s a ailable a ScienceDi ec Jou nal o Magne ic Resonance Open jou nal homepage: www.sciencedi ec .com/jou nal/jou nal-o -magne ic- esonance-open h ps://doi.o g/10.1016/j.jm o.2023.100095 Recei ed 30 No embe 2022; Recei ed in e ised o m 13 Janua y 2023; Accep ed 17 Janua y 2023 Jou nal o Magne ic Resonance Open 14-15 (2023) 100095 2 and in e phases has a c i ical unc ion in achie ing he desi ed p ope - ies. A s uc u al model o desc ibe he kind o in e phases and in e a- cial egions p esen in hese composi es has been p oposed by N i and collabo a o s. This was based on he dis up ion o he o de ed (N-e hyl N-me hyl py olidinium bis( luo osul onyl)imide ([C 2 mpy ][FSI]) OIPC phase a e he addi ion o wo di e en polyme nanopa icles (poly- inylidene luo ide (PVDF) and polys y ene (PS)) and an analysis o he in e ac ion/a ini y be ween hose componen s [11]. Howe e , he ionic anspo mechanisms in OIPC-polyme com- posi es a e s ill a ma e o s udy and i has been p oposed ha he in- c ease in ionic conduc i i y obse ed in such composi es ( ela i e o he pu e OIPC) is associa ed wi h he o ma ion o an in e phase be ween he OIPCs and polyme nanopa icles [11]. This in e phase may ea u e bo h inc eased s uc u al diso de and dynamics, esul ing in an enhancemen in local ion anspo . I has been p oposed ha he highe bulk ionic conduc i i y is a ained when his in e phase o ms a con inuous ne wo k h ough he ma e ials, e med he pe cola ion h eshold [8]. This highligh s he signi icance o unde s anding he e - ec s o in e phase phenomena ha ake place in hese ma e ials. The expe imen al cha ac e iza ion o composi e in e aces and in- e phases can be challenging due o hei dimensions, complexi y, mo phology and inhe en diso de , and his inc eases he di icul y o unde s anding hei o ma ion and p ope ies in e ms o he in e acial s uc u es and chemis ies [12,13]. Many echniques such as X- ay di ac ion, elec on mic oscopy, and a ious o ms o spec oscopy ha e been used o unde s and in e aces. Solid-s a e nuclea magne ic eso- nance (SSNMR) is a powe ul echnique o s udying local diso de and dynamics in ha d o so solids, amo phous, inhomogeneous o c ys al- line ma e ials ha can co-exis in ene gy s o age ma e ials [14]. In solid OIPCs, polyme s and composi es elec oly es, 7 Li, 19 F, and 1 H NMR ha e been implemen ed o s udy he ion dynamics ia line wid h analysis. NMR signals om solid powde samples a e gene ally b oadened by in e ac ions de e mined by he igid-la ice a low empe a u es. As he ion jump a es app oach o exceed he NMR in e ac ion equencies a high empe a u es, peak na owing is obse ed. Thus, wo componen s can o en be dis inguished, a na ow peak ep esen ing a mobile ion ac ion in a diso de ed/dynamic egion such as an in e phase o a g ain bounda y, and a b oad peak ep esen ing he less mobile ion ac ion in a mo e o de ed egion in he ma e ial [15]. In p e ious s udies o [C 2 mpy ][TFSI] and PVDF nanopa icle composi es i was sugges ed ha he o ma ion o diso de ed in e phases led o an enhancemen in ionic conduc i i y o a ound one o de o magni ude in he composi e wi h 10 % o PVDF nanopa icles a 30 ∘C and his u he inc eased wi h inc easing % o he polyme [16]. This was also con i med by he na ow peaks obse ed in he 1 H and 19 F NMR spec a a e he addi ion o PVDF o he composi e and sugges ed ha a ac ion o ions becomes highly mobile. Ion mo ions also in luence NMR elaxa ion p ocesses such as longi- udinal elaxa ion (quan i ied by T 1 ), o e ing an addi ional way o p obe hei dynamics. Fo example, 7 Li T 1 alues a high magne ic ield s eng hs a e sensi i e o mo ions on a imescale o ns, co esponding o ib a ional mo ions o he Li ions and hei su ounding en i onmen [17]. In he sys ems s udied by Meabe and co-wo ke s, whe e di e en concen a ions o LiTFSI sal we e added o a polyme , he highes conduc i i y o 3.2 ×10 −5 Scm −1 a oom empe a u e was obse ed a e adding 30 w % o LiTFSI. In addi ion, a iable empe a u e T 1 measu emen s enabled he calcula ion o he ac i a ion ene gies, co - ela ion imes and quad upola cons an s o he sys ems. The analysis o hese pa ame e s allowed he au ho s o conclude ha as he LiTFSI con en was inc eased, he Li en i onmen became sligh ly mo e sym- me ic due o Li ions coo dina ed by he TFSI anions a he han he e he oxygens o he polyme . This end inc eases wi h he Li sal con en and dec eases he li hium ionic conduc i i y [18]. The Li doping o he OIPC componen in polyme -based composi es also has been s udied. Wang e al. p epa ed composi es by coa ing a Li doped [C 2 mpy ][FSI] laye on comme cial PVDF nanopa icles [19]. They obse ed inc easing ion conduc i i y wi h mass loading con en un il 30 w % o polyme , a e which i s a ed o dec ease. The con- duc i i y was a ibu ed mainly o he conduc i e laye coa ed on he polyme . They also s udied he composi e a e mel ing he OIPC componen and obse ed a dec ease in he ionic conduc i i y. These esul s we e suppo ed by 7 Li NMR linewid h analysis, i was concluded ha an in e ac ion be ween he Li ions and he polyme slow down he Li ion dynamics. C ys alline, Li- ich phases in Li-doped OIPCs can also dec ease he ion conduc i i y. A ecen s udy pe o med by N i and collabo a o s s udied he in e ac ions be ween he OIPC ie hyl (me hyl)phosphonium e a luo obo a e [P 1222 ][BF 4 ] and PVDF nano- pa icles as well as he doping o he OIPC. They obse ed he o ma ion o Li- ich phases in he OIPC la ice a e he Li-doping o he OIPC. This phase was associa ed wi h poo ion anspo p ope ies, bu could be supp essed by he addi ion o PVDF nanopa icles, wi h he PVDF−OIPC in e phase o med in he polyme -based composi e inc easing he local diso de o he OIPC and leading o enhanced ionic conduc i i y [20]. The wo ks discussed abo e demons a e he ex ensi e e o s ha ha e been made o unde s and he in e acial p ope ies ha enhance o dec ease he desi ed p ope ies o solid elec oly es in composi es. He ein, we co ela e mac oscopic p ope ies such as ion conduc i i y wi h he in e acial phenomena in a new chemical a chi ec u e o composi es consis ing o he OIPC [C 2 mpy ][TFSI] and li hium unc- ionalised ac ylic polyme nanopa icles (see Fig. 1). The polyme nanopa icles consis o a c osslinked me hac ylic polyme chain including a side chain ea u ing a unc ional co-monome li hium 1–(3– (me hac yloyloxy)p opylsul onyl)–1–( i luo ome hylsul onyl)imide (LiMTFSI), s uc u ally analogous o he TFSI anion and wi h li hium ions as he ca ion [21,22]. These polyme nanopa icles exhibi a glass ansi ion empe a u e o 122 ∘C, an a e age pa icle size o 95 nm and i was es ima ed ha 80 mol% o he LiMTFSI monome esides a he su ace o he nanopa icles. These composi es we e designed o ake ad an age o he in insic p ope ies o he OIPC like plas ici y, wi h he mechanical s eng h and Li ions con aining ionic unc ionalisa ion o he polyme , and i is an icipa ed ha he o ma ion o in e aces and in- e phases be ween hese componen s will p omo e he ion anspo o he Li ca ions. Addi ionally, he e ec o doping one o he composi es wi h LiTFSI was s udied. I was al eady obse ed ha he addi ion o Li sal o he pu e OIPC inc eases he ionic conduc i i y by h ee o de s o magni ude [9] and in hese composi es i may also p omo e he compa ibili y be ween he polyme and he OIPC. 2. Expe imen al sec ion 2.1. P epa a ion o polyme pa icles: [C 2 mpy ][TFSI] composi es and LiTFSI: [C 2 mpy ][TFSI]: polyme nanopa icle composi e The [C 2 mpy ][TFSI] OIPC and polyme nanopa icles we e syn he- sized ollowing p e iously es ablished p ocedu es [9,21]. Li hium bis ( i luo ome hanesul onyl) imide LiTFSI was pu chased om Sol ay and used as ecei ed. The densi ies o [C 2 mpy ][TFSI] and he polyme nanopa icles we e measu ed a 25 ∘C using a helium pycnome e and co espond o 1.43 g/cm3 and 1.85 g/cm3, espec i ely. Fou polyme -based composi es con aining di e en olume pe cen ages o polyme nanopa icles (10, 15, 25 and 30 (±2) %) we e p epa ed by dissol ing calcula ed amoun s o [C 2 mpy ][TFSI] and polyme nano- pa icles in d y me hanol. Fo he p epa a ion o LiTFSI 0.1 [C 2 mpy ] 0.9 [TFSI]:polyme nanopa icle composi e elec oly e, LiTFSI sal and [C 2 mpy ][TFSI], in [1:9] mola a io, we e also dissol ed in a mix o d y me hanol and ace one, LiTFSI and [C 2 mpy ][TFSI] ep esen 12 and 63 (±2) % o he composi e, espec i ely. Then, 25 (±2) % o polyme nanopa icles we e added in o he solu ion. The esul ing solu ions we e sonica ed and s i ed o o m uni o m suspensions. The suspensions we e cas on Pe i dishes, and he me h- anol was quickly e apo a ed unde a gon low a oom empe a u e. The Y. Ga cía e al. Jou nal o Magne ic Resonance Open 14-15 (2023) 100095 3 samples we e hen packed in o glass ials and he esidual sol en was emo ed on a Schlenk line a 50 ∘C o 24 h. A po ion o he composi es wi h 25 % o polyme nanopa icles and doped wi h LiTFSI we e also hea ed on a Schlenk a 90 ∘C while s i ing o 2 h. The as-p epa ed 25:75 % polyme nanopa icles: OIPC and doped composi es (unhea ed) a e named as-p epa ed and as-p epa ed_doped, espec i ely, while he samples hea ed a 90 ∘C (i.e., mel ing he OIPC componen ) a e named mel ed and mel ed_doped, espec i ely, h oughou he discussion. Finally, all samples we e ans e ed in o an a gon- illed glo e box o s o age and p epa a ion o cha ac e iza ion. 2.2. Cha ac e isa ion 2.2.1. Di e en ial scanning calo ime y (DSC) DSC measu emen s o he composi es we e ca ied ou using a Me - le Toledo DSC1 ins umen equipped wi h STARTeV6.10 so wa e. App oxima ely 7–12 mg o he composi es we e packed in aluminium pans in an ine a mosphe e and es ed o e a empe a u e ange o −120 o 140 ◦C a a scanning a e o 10 ◦C/min. To in es iga e he in- luence o he mal his o y o he samples, h ee he mal cycles we e pe o med o each sample. All samples we e held a an iso he mal empe a u e o −120 ◦C o 30 min be o e hea ing. 2.2.2. Pola ised op ical mic oscopy The OIPC and composi e samples we e i s p epa ed o op ical mic oscopy by sol en cas ing he ma e ial di ec ly on o a mic oscope slide, using he sol en s men ioned in Sec ion 2.1, o s udy he com- posi es as p epa ed, and secondly by placing he samples on a mic o- scope slide, and squeezed wi h a glass co e a e hea ing he ma e ials abo e he mel ing poin o he OIPC in a ho s age. The empe a u e was kep a 95 ∘C o 10 min be o e a cooling a e o 10 ◦C/min was used o p omo e ec ys alliza ion. The polyme nanopa icles we e placed on a mic oscope slide as p epa ed. The images we e cap u ed wi h a pola - ised op ical mic oscope Nikon Eclipse Ti–U wi h 100x magni ica ion a oom empe a u e. 2.2.3. Elec ochemical impedance spec oscopy (EIS) The a e age ionic conduc i i ies o he composi es we e measu ed using a biologic MTZ-35 d i en by MT-lab so wa e. The d ied powde samples we e p essed be ween wo s ainless s eel discs in a sealed KB die using a hyd aulic p ess unde 3 ons o p essu e o 5 min. Each pelle o 3 mm hickness was inse ed in o a he me ically sealed ba el cell. A equency ange o 10 MHz o 1 Hz was s udied using a ol age ampli- ude o 0.01 V wi h empe a u e anging om 30 o 70 ∘C a 10 ∘C s eps. Da a was acqui ed du ing h ee cycles, a hea ing scan om 30 o 70 ∘C, a subsequen cooling scan (70 o 30 ∘C) and inally, ano he hea ing scan, wi h he objec i e o obse e he ep oducibili y and any hys e esis ha migh be p esen . Conduc i i y alues we e calcula ed om Nyquis plo s in which he ouchdown poin o he semi-ci cle co esponds o he bulk esis ance o he ionic conduc ing media. The Nyquis plo s o he composi e as p epa ed and a e mel ing he OIPC componen a 30 ∘C and 50 ∘C a e p esen ed in he suppo ing in o ma ion (Fig. S1). 2.2.4. Solid-s a e MAS NMR (SSNMR) The s udy o he molecula -le el s uc u e o he pu e ma e ials and selec ed composi es by solid-s a e MAS NMR expe imen s was ca ied ou wi h a B uke A ance III 300 MHz wide-bo e spec ome e wi h a 4 mm H/F-X double esonance MAS p obe, a 12 kHz spinning equency, and La mo equencies o 300.13, 75.468, 116.6 MHz o 1 H, 13 C and 7 Li, espec i ely. Samples we e packed and sealed in 4 mm NMR MAS Fig. 1. Molecula s uc u es o (a) he OIPC, (N-me hyl N-e hyl py olidinium bis( i luo ome hanesul onyll)imide [C 2 mpy ][TFSI], (b) he Li sal , Li hium bis ( i luo ome hanesul onyl) imide and (c) he polyme . Y. Ga cía e al. Jou nal o Magne ic Resonance Open 14-15 (2023) 100095 4 o o s in an a gon- illed glo ebox. 19 F and 7 Li MAS NMR we e pe - o med o a e age he chemical shi aniso opy (CSA) e ec s by spin- ning he samples a 54.74∘ wi h espec o he ex e nal ield. A c oss pola iza ion (CP) pulse sequence was pe o med wi h decoupling o inc ease he sensi i i y o 13 C by ans e ing magne iza ion om abundan nuclei like 1 H and 19 F. Then, 1 H– 13 C CPMAS (wi h 1 H decoupling) spec a o he nea OIPC, polyme nanopa icles and selec ed composi es we e acqui ed. Solid sodium luo ide (NaF), li hium chlo ide (LiCl) and wa e we e used as chemical shi e e ences o 19 F (−224.2 ppm), 7 Li (0.0 ppm) and 1 H (4.8 ppm), espec i ely. S a ic (i.e., wi hou MAS) SSNMR expe imen s o s udy dynamics in he pu e ma e ials and selec ed composi es we e ca ied ou wi h a B uke A ance III 500 MHz wide-bo e spec ome e wi h La mo e- quencies o 194.3 and 470.4 MHz, o 7 Li and 19 F, and using a 5 mm HX s a ic p obe. Spec a we e acqui ed wi h a single pulse expe imen using a 90∘ pulse in he case o 1 H and 7 Li and Hahn echo expe imen s o 19 F wi h an echo ime o 5 μ s. The sample empe a u es we e calib a ed using he 207 Pb signal om lead ni a e [23]. Line wid hs epo ed he ein, co espond o he ull wid h a hal o maximum in ensi y (FWHM) o he spec al peak measu ed as a unc ion o empe a u e. The sample empe a u e was equilib a ed a each empe a u e o 10 min. The empe a u e a ia ion o he 7 Li and 19 F spin la ice elaxa ion imes (T 1 ) we e also measu ed o e he same empe a u e ange using a sa u a ion eco e y pulse sequence. Six een elaxa ion delays we e used, a ying om 0.1 ms o 60 s depending on he T 1 alue. The esul ing da a we e i ed using a single exponen ial unc ion using he B uke TopSpin so wa e. The 19 F CSA pa e ns o he pu e OIPC we e also s udied using s a ic Hahn echo expe imen s a −20 ∘C and 20 ∘C and echo delays om 5 μ s o 0.5 s. These measu emen s we e pe o med in a B uke A ance III 500 MHz wide-bo e spec ome e wi h a 4 mm H/F-X-Y iple esonance MAS p obe equipped which enabled he use o 1 H decoupling o emo e he 1 H- 19 F dipola couplings. 3. Resul s and discussion 3.1. The mal analysis 3.1.1. Polyme nanopa icles: [C 2 mpy ][TFSI] composi es The DSC he mal aces o pu e [C 2 mpy ][TFSI] and he polyme nanopa icles: [C 2 mpy ][TFSI] composi es con aining 10, 15, 25 and 30 % o polyme nanopa icles a e p esen ed in Fig. 2. Du ing he i s hea ing cycle, he pu e OIPC goes h ough h ee solid–solid endo he mic phase ansi ions no ed as IV → III, III → II, and II → I wi h onse em- pe a u es a app oxima ely −85, 16 and 45 ◦C, espec i ely, be o e mel ing a 91 ◦C, as epo ed p e iously [9]. These phase ansi ions a e Fig. 2. DSC o (a) i s and (b) second hea ing aces o he nea [C 2 mpy ][TFSI] and he polyme nanopa icles: [C 2 mpy ][TFSI] composi es as a unc ion o he concen a ion o polyme pa icle (10, 15, 25 and 30 %), (c) i s and second hea ing aces o Li doped 25 % polyme nanopa icles: [C 2 mpy ][TFSI] composi e no ed as-p epa ed_doped and mel ed_doped, espec i ely and (d) compa ison be ween he nea OIPC, 25 % polyme nanopa icles: [C 2 mpy ][TFSI] composi es (as- p epa ed and mel ed) and Li doped 25 % polyme nanopa icles: [C 2 mpy ][TFSI] composi e (as-p epa ed_doped and mel ed_doped). Y. Ga cía e al. Jou nal o Magne ic Resonance Open 14-15 (2023) 100095 5 also obse ed in he composi es bu wi h a lowe en halpy (see Table S1 a). Mo eo e , he mel ing peak in he composi es is b oade and i s onse empe a u e is shi ed om 91 o 88 ∘C. In he second hea ing cycle o he nea OIPC, he peaks o he phase ansi ions ge na owe while he mel ing peak ge s b oade which sugges s ha he c ys allini y o he OIPC componen o hese composi es inc eased a e mel ing and sub- sequen cooling (see Fig. 2b). In he DSC aces o he composi es, he phase ansi ions o he OIPC componen can s ill be obse ed du ing he second hea ing cycle bu wi h a lowe in ensi y compa ed o he i s hea ing and shi ed o sligh ly lowe empe a u es (see Fig. 2a and b). These peaks also become b oade as he concen a ion o polyme nanopa icles inc eases, e lec ing an inc easing le el o diso de in he OIPC componen . In addi ion, in he second hea ing ace o he composi es (wi hou addi ional Li sal ) he appea ance o a new peak wi h an onse empe - a u e a 60 ∘C can be obse ed o he le o he mel ing peak. This new peak, which is no obse ed in he i s hea ing ace, becomes mo e p ominen wi h he inc ease in polyme nanopa icle con en . The i s hea ing aces o he composi es a e di e en o he second due o he mel ing o he OIPC componen be ween each scan, which enables ea angemen o he OIPC molecules and ec ys alliza ion o ake place. P io o his, he in e ac ion o he OIPC and he polyme nanopa icles c ea es a local diso de in he OIPC, close o he polyme nanopa icles, as can be in e ed om he b oade mel ing peaks in Fig. 2a. This local diso de close o he polyme nanopa icles is illus a ed schema ically in Fig. 3a. The addi ional mel ing peak in he DSC (second hea ing) scans o he composi es sugges s an addi ional componen , o med a e he mel ing o he OIPC phase, wi h u he inc eased diso de ( ela i e o he pu e OIPC) esul ing in a local dec ease in he OIPC mel ing em- pe a u e [11,24]. This peak indica es he o ma ion o an in e phase whe e he OIPC in e ac s wi h (and possibly mixes wi h) he polyme chains du ing he mel ing o he OIPC componen (Fig. 3b). This egion may also p omo e u he diso de in he local OIPC s uc u e as p o- posed by N i and co-wo ke s [11]. The ac ha he in e phase mel ing peak o e laps wi h he mel ing peak o he pu e OIPC componen in he second hea ing ace o he composi es hinde s he calcula ion and compa ison o he en opy and en halpy o hese wo componen s (peak decon olu ion is ex emely di icul due o he asymme ic shape o hese peaks). These obse a ions a e also suppo ed by a supp essing e ec in he en halpy o he OIPC in he second hea ing in compa ison wi h he i s hea ing and indica e ha he composi e sys ems become mo e diso de ed (see Table S1 a). 3.1.2. Li sal – polyme nanopa icle composi e The e ec s o he addi ion o 1 mol% LiTFSI sal in o he 25 % polyme nanopa icles: [C 2 mpy ][TFSI] composi e was s udied du ing he i s (as-p eap ed_doped) and second (mel ed_doped) hea ing, and he DSC he mal aces o his sample a e p esen ed in Fig. 2c. This concen a ion o Li sal was selec ed based on he inc ease o ionic conduc i i y obse ed in a p e ious s udy o he pu e OIPC [9,25]. The solid-solid phase ansi ions a e obse ed in he composi e doped wi h LiTFSI sal du ing he i s hea ing (as-p eap ed_doped), and he addi ion o LiTFSI sal dec eases he en halpy o he OIPC u he sugges ing ha he local en i onmen o he OIPC become mo e diso - de ed (see Table S1 b). Fu he mo e, hese ansi ions a e b oadened signi ican ly a e mel ing he OIPC componen and eco ding a second hea ing scan (mel ed_doped) indica ing a high deg ee o s uc u al dis- o de wi hin he OIPC; indeed, he nea comple e absence o he solid- solid phase ansi ions in he second scan sugges s ha he OIPC e- ains i s phase I cha ac e e en a lowe empe a u es and i is ollowed by a cold c ys allisa ion be o e mel ing. The mel ing peak o he OIPC in he Li-doped composi es show onse Fig. 3. Schema ic ep esen a ions o (a) local diso de in he OIPC componen close o he polyme nanopa icles be o e he mel ing o he OIPC componen , (b) he o ma ion o an in e phase (o ange egion) a e u he mixing o polyme nanopa icles and he OIPC a e mel ing he OIPC componen , wi h inc eased diso de in he OIPC componen , and (c) doping o he composi e wi h LiTFSI. Schema ic ep esen a ions (d) o he dis ibu ion o Li ions in he polyme , he OIPC la ice and LiTFSI. Y. Ga cía e al. Jou nal o Magne ic Resonance Open 14-15 (2023) 100095 6 empe a u es shi ed o a lowe empe a u e compa ed wi h he undo- ped composi es (70 ∘C du ing he i s hea ing and a 65 ∘C du ing he second hea ing) as shown in Fig. 2d. In addi ion, his peak is signi i- can ly b oadened in he doped sys em. Thus, mo e s uc u al diso de seems o be o med in he OIPC componen o he composi es a e adding LiTFSI. I is accep ed ha in he LiTFSI doped [C 2 mpy ][TFSI] a Li ich eu ec ic solu ion a g ain bounda ies o he OIPC is he leading mechanism o conduc i i y [9]. As a esul o he OIPC ca ions exchanging wi h Li on he su ace o he nanopa icle a u he Li doping o he OIPC componen occu s. This will also c ea e g ea e local ee olume, diso de , and dynamics. Thus, we obse e he o ma ion o wo in e acial egions in he composi es be o e and a e doping wi h Li sal . The i s one shows local s uc u al diso de in he OIPC la ice, which is p esen in he composi es as p epa ed, and will be e e ed h ough he documen as he “in e - acial egion”. The second one is cha ac e ised by u he s uc u al diso de in he OIPC la ice because o he deepe mixing o he com- ponen s o he composi es ha occu s when he OIPC is mel ed, and his will be e e ed o as he “in e phase”. 3.2. C ys alli e mo phology O ganic ionic plas ic c ys als can be op ically aniso opic ma e ials and p esen bi e ingence as a esul o he sho - ange diso de wi hin hei long- ange o de ed c ys alline la ices [26]. On he o he hand, comple ely amo phous ma e ials such as polyme s a e op ically iso opic and do no exhibi s bi e ingence [27]. The mo phology o he OIPC and composi es was s udied quali a i ely using an op ical mic o- scope o ge insigh s abou he c ys alli e size, s uc u e, and dis ibu ion (see Fig. 4). The images we e aken a oom empe a u e a e sol en cas ing he samples o s udy he ma e ials as p epa ed and a e hea ing he samples abo e he mel ing poin o he OIPC on a mic oscope hea ing s age. Pu e [C 2 mpy ][TFSI] in he as p epa ed s a e displays a poly- c ys alline s uc u e o c ys al domains la ge han 500 µm (Fig. 4a and b). The colo s in Fig. 4 ep esen di e en o ien a ions o he c ys alli es delimi ed by g ain bounda ies. A e adding he polyme nanopa icles some egions wi h much smalle c ys als (<50 µm) a e obse ed (see Fig. 4c). The image o he as p epa ed composi e wi h LiTFSI (Fig. 4d) Fig. 4. Pola ised op ical mic og aphs o (a) and (b) pu e OIPC as p epa ed, (c) he 25 % polyme nanopa icles: [C 2 mpy ][TFSI] composi e as p epa ed, (d) Li doped composi e wi h LiTFSI as p epa ed, (e) he OIPC a e mel ing he OIPC componen , ( ) 25 % polyme nanopa icles: [C 2 mpy ][TFSI] composi e a e mel ing he OIPC componen , and (g) doped wi h LiTFSI a e mel ing he OIPC componen . Y. Ga cía e al. Jou nal o Magne ic Resonance Open 14-15 (2023) 100095 7 shows mo e a ia ion in colou indica ing di e en c ys al o ien a ions, sugges i e o an inc eased le el o diso de in his ma e ial han in he as p epa ed polyme -based composi e. A e mel ing and ec ys allisa ion, he nea OIPC shows smalle c ys als on he o de o 100 µm wi h di e en o ien a ions (see Fig. 4e) indica ing ha mo e g ain bounda ies a e o med a e mel ing he OIPC in compa ison wi h he as-p epa ed sample. A e mel ing he OIPC componen in he composi e wi h 25 % o polyme nanopa icles, polyc ys alline sphe uli e-like domains g ea e han 100 µm in size a e obse ed wi h a inc eased amoun o g ain bounda ies han he as- p epa ed sample (Fig. 4 ). This is a ibu ed o he in luence o he polyme nanopa icles on he ec ys allisa ion o he OIPC, which may ac as nuclea ion si es and di ec he c ys al g ow h. Doping he com- posi e wi h LiTFSI also leads o he o ma ion o smalle sphe uli es han hose obse ed a e mel ing he OIPC componen in he polyme -based composi e hus leading o u he educed domain sizes as seen in Fig. 4g, indica ing mo e s uc u al diso de a e doping he composi e wi h Li. These obse a ions again suppo he inc easing diso de obse ed in he DSC hea ing aces a e mel ing he OIPC componen in he composi e wi h li hium doping. These images a e consis en wi h he DSC esul s discussed in he p e ious sec ion, wi h smalle c ys alli es being accompanied by a g ea e o e all le el o diso de ed g ain bounda y egions. Simila ob- se a ions ha e p e iously been made by Ramos and collabo a o s in he s udy o poly(e hylene oxide) (PEO) and OIPCs memb ane composi es [28], who p oposed ha he OIPC migh be con ined by he polyme componen du ing he ec ys allisa ion, u he inc easing he s uc u al diso de . 3.3. Ionic conduc i i y measu emen s The ionic conduc i i ies o he pu e OIPC and a selec ed composi e wi h 25 % o polyme nanopa icles as p epa ed (i.e., as-p epa ed) and a e mel ing he OIPC componen (i.e., mel ed) and he Li doped composi e as p epa ed (i.e., as-p epa ed_doped) and a e mel ing he OIPC componen (i.e., mel ed_doped) we e measu ed as a unc ion o empe a u e h ough EIS expe imen s and he esul s a e p esen ed in Fig. 5a. The expe imen s we e pe o med om 20 o 60 ∘C o a oid he mel ing empe a u e o he OIPC componen . The obse a ion o a single well-de ined semici cle in he Nyquis plo s o all samples (Fig. S1) sugges s a single conduc i i y mechanism is p esen in all samples. A gene al end o inc eased conduc i i y wi h empe a u e can be obse ed o he samples measu ed. I is also obse ed ha he ionic conduc i i y o he composi e (whe e he OIPC componen is mo e diso de ed as obse ed in he DSC hea ing aces) is highe han he pu e [C 2 mpy ][TFSI] du ing he i s hea ing (see Fig. 2a). The e is no obse ed jump in conduc i i y du ing he ansi ion om phase II o I, implying ha his phase ansi ion does no signi ican ly a ec he ion conduc i i y mechanism. A u he inc ease in ion conduc i i y in he composi e is obse ed du ing he second hea ing (mel ed, Fig. 5a). This inc ease in conduc- i i y can be a ibu ed o he o ma ion o he diso de ed in e phase egion be ween he OIPC and polyme componen s as sugges ed by DSC esul s, as well as he la ge amoun o OIPC g ain bounda ies obse ed in he mo phology s udy o he composi es (Fig. 4). The in e phase and g ain bounda ies a e bo h expec ed o ea u e inc eased diso de , dy- namics, and ee olume. Addi ionally, he [C 2 mpy ] ca ions may un- de go exchange wi h he Li on he polyme nanopa icles su ace, he e may be a Li doping e ec on he OIPC ( u he discussed h ough he s uc u al NMR analysis in Sec ion 3.5), ha acili a es he ion conduc i i y. The as-p epa ed_doped composi e shows simila conduc i i ies a lowe empe a u es o he pu e OIPC sugges ing ha he in e acial e- gion be ween he OIPC, polyme nanopa icles and LiTFSI does no imp o e he a e age ion mobili y un il phase I is eached. Con e sely, a e mel ing he OIPC componen in he doped composi e he conduc- i i y is obse ed o inc ease signi ican ly (by mo e han one o de o magni ude a 60 ∘C in compa ison wi h he OIPC). This can be a ibu ed o an inc ease in he mobili y o he ions loca ed in he diso de ed in e phase o med be ween he OIPC and polyme nanopa icles as a esul o he ini ial exchange be ween OIPC ca ions and Li on he poly- me nanopa icles ha c ea e a pa ial doping o he OIPC and he u he doping o he OIPC a e adding LiTFSI leading o a highe conduc i i y in mel ed_doped compa ed o mel ed (Fig. 5). These ob- se a ions suppo he DSC and mo phology analysis whe e mo e s uc u al diso de is obse ed in he doped composi e a e mel ing he OIPC componen in compa ison wi h he as-p epa ed doped composi e. Howe e , he mel ed_doped showed lowe conduc i i y han he OIPC doped wi h 0.9 mol% o LiTFSI s udied p e iously [9], which showed conduc i i y o almos wo o de o magni ude (i.e., om 10 -8 o 10 -6 S cm -1 ) la ge han he OIPC a 27 ∘C indica ing ha he polyme nano- pa icles es ic he mobili y o he ions in he composi e in compa ison wi h he doped OIPC. 3.4. Solid-s a e NMR analysis: s uc u e The pu e [C 2 mpy ][TFSI], polyme nanopa icles, and composi es wi h 25:75 % polyme nanopa icles: [C 2 mpy ][TFSI] as p epa ed (as- p epa ed) and a e mel ing he OIPC componen (mel ed), as well as he same composi e wi h 1 mol% LiTFSI sal inco po a ed as p epa ed (as- Fig. 5. Ion conduc i i y as a unc ion o he empe a u e o (a) he composi es wi h polyme nanopa icles concen a ion o 25 % as p epa ed (as-p epa ed) and a e mel ing he OIPC componen (mel ed), and (b) he LiTFSI doped composi e as p epa ed (as-p epa ed_doped) and a e mel ing he OIPC componen (mel- ed_doped) agains he ion conduc i i y o [C 2 mpy ][TFSI]. Y. Ga cía e al. Jou nal o Magne ic Resonance Open 14-15 (2023) 100095 8 p epa ed_doped) and a e mel ing he OIPC componen (mel ed_doped) we e s udied by 13 C CPMAS and 19 F and 7 Li MAS NMR expe imen s. The 1 H– 13 C CPMAS NMR spec a o hese samples and he assignmen o ca bon esonances o he OIPC and he polyme nanopa icles a e p esen ed in Fig. 6. The c ys alline s uc u e o he OIPC esul s in na owe 13 C peaks han he signals om he polyme whe e he ca bon si es exis in a locally diso de ed s uc u e. The as-p epa ed composi e spec um e- sembles he pu e OIPC, and polyme signals supe imposed wi h sligh ly b oade OIPC peaks shi ed o a lowe chemical shi , sugges ing ha he chemical en i onmen o he ca bons in he OIPC is al e ed o some ex en by he addi ion o polyme nanopa icles and ha he OIPC and polyme ha e mixed in he in e acial egion. On he o he hand, in he mel ed composi e some changes can be obse ed in he shape and in- ensi y o some o he polyme signals and in he OIPC linewid h o he 13 C peaks whe e he na owe 13 C peaks e lec s he inc ease o he local dynamics o he OIPC ca ions (i.e., o a ions) in his composi e. In addi ion, hese signals a e shi ed o a lowe chemical shi han in mel ed composi e and sugges ha he chemical en i onmen o he OIPC ca ions was al e ed a e he addi ion o he polyme nanopa icles, consis en wi h some mixing wi h he OIPC componen in he mel s a e. In he composi e doped wi h he Li sal as p epa ed, changes in he in ensi y and b oad signals o he ca bon en i onmen s ha come om he polyme a e also obse ed in a simila magni ude o mel ed_doped composi e. The 13 C peaks om he OIPC componen show simila line- wid hs han he pu e OIPC bu a e shi ed o lowe chemical shi s han he as-p epa ed and mel ed composi es (see Fig. S2), sugges ing ha he addi ion o LiTFSI u he changes he local en i onmen a ound he OIPC ca ions. In addi ion, a new peak a 180 ppm is obse ed in bo h doped composi es. This is a ibu ed o an in e ac ion be ween he Li ca ion o he Li sal wi h he elec onega i e oxygen o he ca bonyl g oups a he su ace o he polyme nanopa icles. The changes in he chemical en i onmen o he OIPC ca ion signals indica ed by he lowe chemical shi s sugges an exchange o hese ca ions wi h he Li ions on he polyme nanopa icles, as will be dis- cussed la e , ha allows an ini ial Li doping o he OIPC in he com- posi es as-p epa ed and mel ed and a u he doping a e adding LiTFSI. These doping e ec s no only inc eased local diso de bu also local dynamics o he OIPC ca ions. I should be no ed ha he 13 C signals om he CF 3 g oups o he polyme nanopa icles and OIPC a e no obse ed in hese spec a due o he use o c oss pola isa ion om 1 H. Changes in he a e age chemical en i onmen o he Li ions we e obse ed in he composi es wi h espec o he polyme nanopa icles as can be seem in Fig. 7. A b oad 7 Li MAS NMR peak is obse ed o he polyme nanopa icles as was expec ed due o he inhe en s uc u al diso de in his ma e ial. In gene al, he composi es showed asymme ic 7 Li peak wid hs wi h a no iceable shi o lowe chemical shi s wi h espec o he polyme , indica ing a change in he su ounding s uc u al en i onmen o he Li ions. In he case o he as-p epa ed composi e, he peak was shi ed as a esul o he in e ac ion o he Li ions wi h he su ounding OIPC. Once he OIPC is mel ed in he composi e, he OIPC and polyme componen s become mo e in ima ely mixed and as a esul a u he shi and b oade peak is obse ed o mel ed composi e, indica i e o mo e s uc u al diso de a ound he Li ions in he in e phase. A e doping he composi e Fig. 6. (a) 1 H– 13 C CPMAS NMR o [C 2 mpy ][TFSI], polyme , 25:75 % polyme nanopa icles: [C 2 mpy ][TFSI] composi es as p epa ed (as-p epa ed) and a e mel ing he OIPC componen (mel ed), and Li doped composi es as p epa ed (as-p epa ed_doped) and a e mel ing he OIPC componen (mel ed_doped). Molecula s uc u es o (b) [C 2 mpy ][TFSI] and c) polyme wi h pa ial assignmen o he 13 C peaks o ce ain s uc u al si es. Fig. 7. 7 Li MAS NMR spec a o polyme nanopa icles, 25:75 % polyme nanopa icles: [C 2 mpy ][TFSI] composi es as p epa ed (as-p epa ed) and a e mel ing he OIPC componen (mel ed), and Li doped composi es as p epa ed (as-p epa ed_doped) and a e mel ing he OIPC componen (mel ed_doped). Y. Ga cía e al. Jou nal o Magne ic Resonance Open 14-15 (2023) 100095 9 wi h he Li sal he 7 Li signals in as-p epa ed_doped and mel ed_doped appea e y sligh ly u he shi ed o he igh , bu a e qui e simila o he spec um o mel ed composi e. The changes obse ed in he shape, linewid h and chemical shi in he composi es sugges some ype o complexa ion o exchange o he li hium on he polyme nanopa icles wi h o he anions, in his case wi h he OIPC ca ions. This exchange is g ea e in he composi es a e mel ing he OIPC componen (i.e., mel ed and mel ed_doped) and esul s in in e phases wi h inc eased diso de ha acili a e he ion conduc i i y as discussed in Sec ions 3.1–3.3. 19 F MAS NMR spec a we e also acqui ed om he OIPC, polyme nanopa icles and composi es, and a e shown in Fig. 8. A single 19 F iso opic chemical shi is obse ed o he pu e OIPC, polyme nano- pa icles and all ou composi es. Howe e , he 19 F signal o he polyme is much b oade han ha o he OIPC and composi es due o he highe le el o local s uc u al diso de a ound he polyme anionic g oups. The 19 F spec a o he composi es appea e y simila o ha o he OIPC and his is due o he dominance o he OIPC TFSI signal. Howe e , a sligh b oadening o he signal obse ed in he doped composi es sugges s some inc eased s uc u al diso de a e he addi ion o LiTFSI. Due o he composi ion, he b oade signal om he anionic polyme g oups will show a much lowe in ensi y and is hus somewha hidden unde he sha pe TFSI signal (see peak decon olu ion in Fig. S3). In e ac ions such as chemical shi aniso opy (CSA) a e inhe en o s a ic 19 F NMR spec a and a e ela ed o he chemical en i onmen , so can p o ide in o ma ion bo h on he s uc u e (e.g. con o ma ion) and molecula dynamics such as o a ions o eo ien a ions o TFSI anions [29]. The e o e, s a ic 19 F NMR spec a we e also acqui ed om hese samples using a Hahn echo pulse sequence. Addi ionally, 1 H decoupling was used o emo e he he e onuclea dipola in e ac ions wi h he p o ons p esen on he [C 2 mpy ] ca ion, p o iding sha pe 19 F CSA pa e ns. In e es ingly, he i ing o he [C 2 mpy ][TFSI] s a ic Hahn echo NMR spec um wi h a sho echo delay ime a 20 ∘C equi ed h ee dis inc CSA pa e ns (Fig. 9 and Table S2) despi e only a single iso opic 19 F signal being obse ed by MAS NMR (Fig. 8). These CSA pa e ns a e pos ula ed o a ise om di e en con o - ma ions o he TFSI anion (i.e., ans, cis and gauche). P e iously, hese h ee di e en con o ma ions o he TFSI ion we e obse ed in liquid LiTFSI-ace amide elec oly es wi h mola a ios o 1:2, 1:4, and 1:6 using DFT simula ions [30]. I was obse ed ha he gauche con o ma ion was p e e ed when he concen a ion o ace amide molecules was low (i.e., elec oly e wi h mola a io o 1:2) because i can help o educe he epulsion be ween Li ca ions in close con ac in he elec oly e. Howe e , a highe ac ion o TFSI anions adop ed he cis con o ma ion in he elec oly e wi h high ace amide concen a ion whe e s ong in- e ac ions be ween he TFSI anions and Li ca ions wi h ace amide occu . Finally, he au ho s obse ed ha TFSI anions adop ed p e e en ially he ans con o ma ion wi h lowe ene gy in he elec oly e wi h mola a io o 1:4. The cis and ans con o ma ions ha e also been obse ed by solid-s a e NMR, showing di e en iso opic chemical shi s [31]. The single iso opic signal we ha e obse ed in he MAS spec um indica es ha hese h ee con o ma ions mus unde go exchange on he imescale o he MAS NMR signal acquisi ion (a ound 5 ms). The assignmen o hese dis inc CSA pa e ns o speci ic con o ma ions would equi e he pa ame e s o be calcula ed om he di e en s uc u es, which is beyond he scope o his a icle. Fu he e idence o he exchange be ween hese si es is p o ided by he e olu ion o he spec al line shapes as he empe a u e and echo ime a e a ied (Fig. S4). 3.5. Solid-s a e NMR analysis: dynamics The analysis o SSNMR line wid hs and T 1 elaxa ion imes we e employed in his s udy. These expe imen s a e sensi i e o o a ional and ansla ional dynamics, and quan i a i e and quali a i e in o ma- ion on dynamics can be ex ac ed om hese pa ame e s based on hei empe a u e dependence. The ion dynamics in he OIPC, polyme nanopa icles and composi es we e s udied using solid-s a e 19 F, 1 H and 7 Li NMR ca ied ou on s a ic samples. 3.5.1. Line wid h analysis Polyme nanopa icles. The e ec o empe a u e on he li hium en i- onmen and dynamics in he pu e polyme nanopa icles was s udied by 7 Li single pulse s a ic NMR expe imen s wi h he sample hea ed om 20 o 160 ∘C, ollowed by cooling (Fig. 10). Du ing hea ing om 20 o 100 ∘C, he 7 Li line wid h dec eases om a ound 2000 o 1200 Hz, e lec ing inc eased dynamics o he Li ca ions such as as e ion jumps ha esul in mo ional a e aging [17,32]. A d ama ic inc ease in he 7 Li line wid hs is hen seen abo e 100 ◦C, eaching a ound 3400 Hz a 160 ◦C. When he sample is cooled om 160 ∘C a u he inc ease o he line wid h alues is obse ed. This beha iou is ela ed o he eo ganiza ion o he polyme s uc u e. Ini ially, he li hium ions a e loca ed p ima ily on he su ace o polyme nanopa icles associa ed wi h he anion o he side chain, and Fig. 8. 19 F MAS NMR spec a o [C 2 mpy ][TFSI], polyme , 25:75 % polyme nanopa icles:[C 2 mpy ][TFSI] composi es as p epa ed (as-p epa ed) and a e mel ing he OIPC componen (mel ed), and Li doped composi es as p epa ed (as-p epa ed_doped) and a e mel ing he OIPC componen (mel ed_doped). Side bands a e indica ed wi h (*) in each spec um. Fig. 9. Fi ing s a ic 19 F NMR CSA pa e ns o [C 2 mpy ][TFSI] a 20◦C o h ee di e en con o ma ions o he TFSI anion. Y. Ga cía e al.