Self-adaptive multiblock-copolymer-based hybrid solid-state electrolyte for safe and stable lithium-metal battery

The dramatic volume change during the Li plating/stripping process has aroused brittle solid electrolyte interphase as well as weak interfacial compatibility between electrolyte and electrode, which results in capacity fading and safety hazards. We design elastic multiblock copolymers (mBCPs) with excellent extensibility up to 600% to address this problem. The best recovery rate of mBCP is 82% after 100 times of cyclic tensile tests. The mBCPs are regarded as elastomers that enable close contact with electrode surface during cycling. The elastic mBCPs are then mixed with lithium salt and high ionic conductivity inorganic ceramics to prepare hybrid solid-state electrolytes (HSSEs). The HSSEs are expected to possess self-adaptive property making good interfacial connection due to the mBCPs. The best HSSEs demonstrate high ionic conductivity of 0.14 mS cm(-1) with a Li ion transference number of 0.55 and wide electrochemical window of 5.2 V at 25 degrees C. Excellent cycling performance with long battery life is achieved by utilizing the self-adaptive HSSE: the Li metal electrode cycled for 150 times retains 96% coulombic efficiency in Li/HSSE/LiFePO4 cells, and stable cycling of 500 h is achieved in the symmetric cells. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study investigates the issues caused by volume changes in lithium metal batteries and proposes the use of elastic multiblock copolymers to address these challenges. The hybrid solid-state electrolytes exhibit high ionic conductivity and self-adaptive properties, which improve the stability and lifespan of the batteries.