Multifunctional self-reconstructive cathode/electrolyte interphase layer for cobalt-free Li-rich layered oxide cathode

Abstract

High-capacity cobalt-free lithium-rich manganese-based oxide (LMNO) is a crucial representative of high-energy-density lithium-ion batteries (LIBs). However, the collaboration failure mechanism (CFM) between LMNO and electrolyte always leads to irreversible oxygen loss, harmful electrolyte decomposition, aggravated structural rearrangement, and severe interfacial side reactions, thereby triggering a sustained decrease in electrochemical performance. Therefore, capturing reactive oxygen species and generating the cathode-electrolyte-interface (CEI) layer shows the potential to resolve these typical issues induced by CFM propagation. Herein, an amine-functionalized mesoporous molecular sieve (NASM) additive with active oxygen/water scavenging capability was designed to construct a multifunctional self-reconstructive CEI layer with modified mechanical/electrochemical stability. Meanwhile, the additive-induced anti-fluoridation protective layer was synchronously generated to synergistically regulate the diffusion of lithium ions and electrons during the CEI reconstruction process. Benefiting from these advantages, the LMNO cathode with NASM-containing electrolyte presented outstanding cycle stability, with only ∼0.06% (1 C) and ∼0.07% (5 C) capacity attenuation per cycle during long-term cycling. This additive-induced multifunctional self-reconstructive CEI layer design provides new insights into reducing undesired CFM propagation to achieve a high-stability and high-energy-density LMNO system for advanced LIBs.