Abstract
In Na-ion batteries,O3-type layered oxide cathode materials encounter challenges such as particle cracking,oxy-gen loss,electrolyte side reactions,and multi-phase transitions during the charge/discharge process.This study focuses on surface coating with NiTiO3 achieved via secondary heat treatment using a coating precursor and the surface material.Through in-situ x-ray diffraction(XRD)and differential electrochemical mass spectrometry(DEMS),along with crystal structure characterizations of post-cycling materials,it was determined that the NiTiO3 coating layer facilitates the forma-tion of a stable lattice structure,effectively inhibiting lattice oxygen loss and reducing side reaction with the electrolyte.This enhancement in cycling stability was evidenced by a capacity retention of approximately 74％over 300 cycles at 1 C,marking a significant 30％improvement over the initial sample.Furthermore,notable advancements in rate performance were observed.Experimental results indicate that a stable and robust surface structure substantially enhances the overall stability of the bulk phase,presenting a novel approach for designing layered oxide cathodes with higher energy density.
基金项目
National Key R&D Program of China(2022YFB2402500)
National Natural Science Foundation of China(52122214)
National Natural Science Foundation of China(92372116)
National Natural Science Foundation of China(52394174)
Youth Innovation Promotion Association of the Chinese Academy of Sciences(2020006)
Jiangsu Province Carbon Peak and Neutrality Innovation Program(Industry tackling on prospect and key technology)(BE2022002-5)
Guangxi Power Grid Project(GXKJXM20210260)
NETL
NSTL
万方数据