电容型锂离子电池脉冲放电性能及其失效机理分析OA

Capacitor-type lithium-ion batteries are attracting increasing interest for applications such as smart grids,electromagnetic energy systems,and power supplies for artificial intelligence data center.However,rapid capacity degradation under high-rate conditions remains a critical limitation to their further development.Herein,a capacitor-type battery using LiNi1/3Co1/3Mn1/3O2(NCM333)as the cathode and hard carbon(HC)as the anode(NCM333||HC)is systematically investigated to elucidate its failure mechanisms under high-power conditions.The results demonstrate that the capacitor-type battery maintains a high discharge capacity even at a current rate of 14 C.Under shallow charge-discharge conditions of 10 C and 40％depth of discharge(DoD),the capacity retention remains above 90％after 40000 cycles.By contrast,under high-power operating conditions involving 1 C charging,10 C discharging,and 100％DoD,the capacity retention decreases only to 75％after 200 cycles.The structure,morphology,surface chemical states,and elemental distribution of the electrodes before and after cycling were characterized using scanning electron microscopy,X-ray photoelectron spectroscopy,and inductively coupled plasma optical emission spectrometry.The results indicate that high-power cycling causes cracking of the cathode particles and irreversible expansion of the layered NCM333 structure.After cycling,Ni,Co,and Mn are detected on the anode,confirming the dissolution of transition metals from the cathode,their migration across the separator,and subsequent deposition on the anode.This study elucidates the failure mechanisms of the NCM333||HC capacitor-type battery under high-power conditions and provides insights for the future optimization of capacitor-type lithium-ion batteries.