Enhancing interfacial stability in solid-state lithium batteries with polymer/garnet solid electrolyte and composite cathode framework

The solid-state lithium battery is considered as an ideal next-generation energy storage device owing to its high safety, high energy density and low cost. However, the poor ionic conductivity of solid electrolyte and low interfacial stability has hindered the application of solid-state lithium battery. Here, a flexible polymer/garnet solid electrolyte is prepared with poly(ethylene oxide), poly(vinylidene fluoride), Li6.75La3Zr1.75Ta0.25O12, lithium bis(trifluoromethanesulfonyl)imide and oxalate, which exhibits an ionic conductivity of 2.0 x 10(-4) S cm(-1) at 55 degrees C, improved mechanical property, wide electrochemical window (4.8 V vs. Li/Li+), enhanced thermal stabilities. Tiny acidic OX was introduced to inhibit the alkalinity reactions between Li6.75La3Zr1.75Ta0.25O12 and poly(vinylidene fluoride). In order to improve the interfacial stability between cathode and electrolyte, an Al2O3 @LiNi0.5Co0.2Mn0.3O2 based composite cathode framework is also fabricated with poly(ethylene oxide) polymer and lithium salt as additives. The solid-state lithium battery assembled with polymer/garnet solid electrolyte and composite cathode framework demonstrates a high initial discharge capacity of 150.6 mAh g(-1) and good capacity retention of 86.7% after 80 cycles at 0.2 C and 55 degrees C, which provides a promising choice for achieving the stable electrode/electrolyte interfacial contact in solid-state lithium batteries. (c) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

Automated summary

The newly prepared flexible polymer/garnet solid electrolyte exhibits a high ionic conductivity, improved mechanical properties, a wide electrochemical window, and enhanced thermal stability, providing a stable electrode/electrolyte interfacial contact for solid-state lithium batteries.