Towards an in-Depth Understanding of Single-Ion Conducting Polymer Electrolytes for Lithium-Metal Batteries

Abstract

Recently, we have reported a new polyarylene-based single-ion conducting multi-block copolymer electrolyte providing very high ionic conductivities of about 1 mS cm-1 at ambient temperature and excellent cycling stability of LiNMC811 (LiNi0.8Mn0.1Co0.1O2) cells – even at 0 °C.1–3 Further improvement of this new electrolyte system, however, requires an in-depth understanding of ideally each single functional unit in the polymer.Herein, we present some of our latest results on the experimental and theoretical investigation of stepwise modified copolymers in order to decipher the impact of the different functional groups on the eventual mechanical, thermal, chemical, and electrochemical behavior. This stepwise modification includes, amongst others, the replacement of the biphenyl unit by a series of bisphenol derivatives and the variation of the ionophobic and ionophilic block. The former approach provides the unique opportunity to investigate the influence of the monomer substitution pattern, while the latter unveils some rather unexpected findings concerning the impact of the lithium concentration in the electrolyte. References H.-D. Nguyen et al., Energy Environ. Sci., 11, 3298–3309 (2018).D. Steinle et al., J. Solid State Electrochem., 26, 97–102 (2022).Z. Chen et al., Nano Energy, 77, 105129 (2020).