Expanding the chemistry of single‐ion conducting poly(ionic liquid)s with polyhedral boron anions

Abstract

The synthesis of a new family of single‐ion conducting random copolymers bearing polyhedral boron anions is reported. For this purpose two novel ionic monomers, namely [B12H11(OCH2CH2)2OC(O)C(CH3)CH2]2−[(C4H9)4N+]2 and [8‐(OCH2CH2)2OC(O)C(CH3)CH2‐3,3′‐Co(1,2‐C2B9H10)(1′,2′‐C2B9H11)]−K+, having methacrylate function, diethylene glycol bridge and closo‐dodecaborate or cobalt bis(1,2‐dicarbollide) anions were designed. Such monomers differ from previously reported ones by (i) chemically attached highly delocalized boron anions, by (ii) valency of the anion (divalent anion and monovalent one) and by (iii) the presence of oxyethylene flexible spacer between the methacrylate group and bonded anion. Their free radical copolymerization with poly(ethylene glycol) methyl ether methacrylate and subsequent ion exchange provided lithium‐ion conducting polyelectrolytes showing low glass transition temperature (−53 to −49 °C), ionic conductivity up to 9.1 × 10−7 S cm−1, lithium transference number up to 0.61 (70 °C) and electrochemical stability up to 4.1 V versus Li+/Li (70 °C). The incorporation of propylene carbonate (20–40 wt%) into the copolymers resulted in the enhancement of their ionic conductivity by one order of magnitude and significantly increased their electrochemical stability up to 4.7 V versus Li+/Li (70 °C). © 2019 Society of Chemical Industry

Synthesis and study ofC-substituted methylthio derivatives of cobalt bis(dicarbollide)

“…[1][2][3][4][5] Among the various derivatives of carboranes, special attention is paid to p-complexes of transition metals with carborane ligands, called metallacarboranes. The most known of them, cobalt bis(dicarbollide) [3,3 0 -Co(1,2-C 2 B 9 H 11 ) 2 ] À attracts increasing interest from researchers working in various elds from medical chemistry to [6][7][8][9][10][11] materials science [12][13][14][15][16][17][18] to due to its extraordinary high stability, low toxicity 19 and almost unlimited possibilities for chemical modication. 20,21 Recently, we suggested that cobalt bis(dicarbollide) can be used as a structural element in the design of molecular switches.…”

Unique Carbonate-Based Single Ion Conducting Block Copolymers Enabling High-Voltage, All-Solid-State Lithium Metal Batteries

“…We demonstrated previously ,, that the highest ionic conductivity for linear methacrylate-based SICPs can be achieved by copolymerization of lithium ion containing monomers with PEGM. The presence of oxyethylene fragments in the side chain of poly­(PEGM), by analogy to PEO, significantly improves the solubility of ionic species, thus facilitating their dissociation and correspondingly enhancing the ionic conductivity of the resulting copolymers.…”

“…The investigation of block copolymer synthesis started with the RAFT polymerization of LiM monomer (LiMTFSI) using the poly­(TMC) precursor as the macro-RAFT transfer agent and AIBN as the initiator. DMF was chosen as a solvent due to its ability to dissolve both poly­(TMC) and LiM as well as because its utilization in (co)­polymerization of LiM monomer allowed for achieving high yields and high molecular weights of the resulting polyelectrolytes. ,,− Using the optimal reaction conditions determined previously for RAFT polymerization of LiM ([AIBN]:[macro-RAFT] = 1:5 by mol, [DMF]:[poly­(TMC) + LiM] = 3:1 by weight), a set of poly­[TMC n - b -LiM m ] block copolymers (Table , copoly1–3) targeting different degrees of polymerization, were successfully prepared. The obtained ionic block copolymers were firm and densely packed yellowish rubber-like materials.…”

Developing Single‐Ion Conductive Polymer Electrolytes for High‐Energy‐Density Solid State Batteries

“…Most of the attention on SICPEs is focused on ion pairing and cation–dipole interactions, which directly govern the dissociation and transport of Li + . Nevertheless, the interaction between anions and polymer matrices also correlates [ 66 ] with the movement ability and the ionic conductivity of SICPEs, mainly in two ways: [ 67 ] 1) The rigid groups in the polyanions, for example, phenyl groups in PSTFSI, would increase the T g of SICPEs. 2) Strong ionic crosslinking between the polyanion and polymer matrix through Li + hinders segmental mobility.…”