摘要
Microspinel LiMn_(2)O_(4)(LMO)is a widely used cathode material in power lithium-ion batteries.However,inevitable Mn dissolution and dynamic phase instability will cause the degradation of microspinel LMO during cycling.Here,a low-tortuosity LMO(LMO-LT)electrode is fabricated by an ice-templating method,which exhibits enhanced dynamic phase stability,alleviated Mn dissolution,and rare particle microcracks during cycling.It is shown that the low-tortuosity electrode enables fast lithium-ion diffusion and thus small concentration polarization,leading to uniform electrochemical reaction within microregions of the LMO-LT electrode.Furthermore,the fast lithium-ion transport kinetics and even mesoscopic scale reactions of the LMO-LT electrode effectively alleviate irreversible phase transition and Mn dissolution as well as suppress crack generation in LMO particles.As a result,the full cell[negative-to-positive capacity ratio(N/P)=1.1]with thick LMO-LT cathode(13 mg cm^(−2))and Li_(4)Ti_(5)O_(12) anode sustains 80.0%capacity over 200 cycles.The LMO-LT electrode further delivers 78.9%capacity of that at 0.1 C at the high rate of 5 C.This work provides an important strategy to enhance dynamic phase stability and suppress Mn dissolution at the mesoscopic scale,promoting the development of high-performance LMO electrodes.
基金
We thank the Analytical and Testing Center of HUST for allow-ing us to use its facilities.Funding:This work was supported by the National Key Research and Development Program of China(grant no.2022YFB2404800)
the National Natural Science Foundation of China(no.U1966214).Author contri-butions:R.H.:conceptualization,data curation,methodology,investigation,and writing-review and editing,S.L.:data cura-tion and investigation,M.L.:data curation,M.Q.:methodology,W.Z.:visualization,S.C.:supervision,funding acquisition,and resources,J.X.:conceptualization,supervision,funding acquisi-tion,resources,and writing-review and editing.Competing interests:The authors declare that they have no competing interests.
