A New Strategy to Stabilize Capacity and Insight into the Interface Behavior in Electrochemical Reaction of LiNi_0.5Mn_1.5O₄/Graphite System for High-Voltage Lithium-Ion Batteries

The performance of CEI and SEI configuration and formation mechanism on the cathode and anode side for LiNi_0.5Mn_1.5O₄/natural graphite (LNMO/NG) batteries is investigated, where series permutations of the NG electrodes modified with TEOS species as the anode for the LNMO full cells. It is believed that the excellent long-term cycling performance of LNMO/NG full cells at the high voltage is a result of alleviating the devastated reaction to form the CEI and SEI on the both electrodes with electrolyte, respectively. At a voltage range from 3.4 to 4.8 V for the LNMO full cells, 95.0% capacity retention after 100 cycles is achieved when cycled with TEOS-modifying NG anode. This mechanism may be explained that eliminating the HF and absorbing water impurities in the electrolyte by introducing the TEOS group, which can transform the SiO₂ species that react with the acid of HF at the organic solvent environment instead of destroying/forming the anode SEI and attacking the LNMO spinel structure to form the dense and high resistance CEI, meanwhile the SiO₂ species will absorb the water molecule and precipitate into the anode surface further stabilizing the SEI configuration during the cycling

Integrated Design for Regulating the Interface of a Solid-State Lithium–Oxygen Battery with an Improved Electrochemical Performance

A composite solid-state electrolyte (SSE) with acceptable safety and durability is considered as a potential candidate for high-performance lithium–oxygen (Li–O2) batteries. Herein, to address the safety issues and improve the electrochemical performance of Li–O2 batteries, a solvent-free composite SSE is prepared based on the thermal initiation of poly(ethylene glycol) diacrylate radical polymerization, and an integrated battery is achieved by injecting an electrolyte precursor between electrodes during the assembly process through a simple heat treatment. The Li-metal symmetric cells based on this composite SSE achieve a critical current density of 0.8 mA cm–2 and a stable cycle life of over 900 h at a current density of 0.2 mA cm–2. This composite SSE effectively inhibits the erosion of O2 on the Li metal anode, optimizes the interface between the electrolyte and cathode, and provides abundant reaction sites for the electrochemical reactions during cycling. The integrated solid-state Li–O2 battery prepared in this work achieves stable long cycling (118 cycles) at a current density of 500 mA g–1 at room temperature, showing the promising future application prospects