Abstract
The Na-deficient P3-type layered oxide cathode material usually experience complex in-plane Na+/vacancy ordering rearrangement and undesirable P3-03 phase transitions in the high-voltage region,leading to inferior cycling performance.Additionally,they exhibit unsatisfactory stability when exposed to water for extended periods.To address these challenges,we propose a Cu/Ti co-doped P3-type cath-ode material(Na0.67Ni0.3Cu0.03Mn0.6Ti0.07O2),which effectively mitigates Na+/vacancy ordering and sup-presses P3-O3 phase transitions at high voltages.As a result,the as-prepared sample exhibited outstand-ing cyclic performance,with 81.9％retention after 500 cycles within 2.5-4.15 V,and 75.7％retention after 300 cycles within 2.5-4.25 V.Meanwhile,it demonstrates enhanced Na+transport kinetics during desodi-ation/sodiation and reduced growth of charge transfer impedance(Rct)after various cycles.Furthermore,the sample showed superb stability against water,exhibiting no discernible degradation in structure,mor-phology,or electrochemical performance.This co-doping strategy provides new insights for innovative and prospective cathode materials.
维普
万方数据