表面限域掺杂提升高比能正极材料稳定性  

Localized Surface Doping for Improved Stability of High Energy Cathode Materials

作　　者：张思东 刘园 祁慕尧 曹安民[1,2] Sidong Zhang;Yuan Liu;Muyao Qi;Anmin Cao(CAS Key Laboratory of Molecular Nanostructure and Nanotechnology,Beijing National Laboratory for Molecular Sciences,Institute of Chemistry,Chinese Academy of Sciences(CAS),Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;Nanozyme Medical Center,School of Basic Medical Sciences,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]中国科学院化学研究所,分子纳米结构与纳米技术院重点实验室,北京分子科学国家中心,北京100190 [2]中国科学院大学,北京100049 [3]郑州大学基础医学院纳米酶医学中心,郑州450001

出　　处：《物理化学学报》2021年第11期75-87,共13页Acta Physico-Chimica Sinica

基　　金：中国科学院前沿科学研究计划(ZDBS-LY-SLH020);北京分子科学国家实验室(BNLMS-CXXM-202010);国家自然科学基金(22025507,21931012);高能量密度硅基动力电池的研发与产业化创新团队(2018607219003)资助项目。

摘　　要：锂离子电池在便携式电子设备、电动汽车等领域得到了广泛应用,随着对电池能量密度需求的日益增加,高比能、高稳定正极材料的开发成为相关研究的重点和难点。而正极材料比能量的提升又同时伴随着其自身结构稳定性和循环稳定性的挑战,使得锂离子电池的稳定性、安全性成为制约其应用的关键挑战。本文以高比能正极材料为研究对象,对影响正极材料结构稳定性、电化学稳定性等一系列因素进行介绍和分析,再从目前改善材料结构稳定性的有效策略入手,对表面限域掺杂这一特殊稳定策略的实现途径、稳定机制进行了总结和分析,并结合现有不同表面修饰方法进行分析和评述,对高比能正极稳定性提升的可能策略及方向进行了展望。Lithium ion batteries(LIBs) have broad applications in a wide variety of a fields pertaining to energy storage devices. In line with the increasing demand in emerging areas such as long-range electric vehicles and smart grids, there is a continuous effort to achieve high energy by maximizing the reversible capacity of electrode materials, particularly cathode materials. However, in recent years, with the continuous enhancement of battery energy density, safety issues have increasingly attracted the attention of researchers, becoming a non-negligible factor in determining whether the electric vehicle industry has a foothold. The key issue in the development o battery systems with high specific energies is the intrinsic instability of the cathode, with the accompanying question of safety. The failure mechanism and stability of high-specific-capacity cathode materials for the nex generation of LIBs, including nickel-rich cathodes, high-voltage spine cathodes, and lithium-rich layered cathodes, have attracted extensive research attention. Systematic studies related to the intrinsic physical and chemical properties of different cathodes are crucial to elucidate the instability mechanisms of positive active materials. Factors that these studies must address include the stability under extended electrochemical cycles with respect to dissolution of metal ions in LiP F;-based electrolytes due to HF corrosion of the electrode;cation mixing due to the similarity in radius between Li;and Ni;oxygen evolution when the cathode is charged to a high voltage;the origin of cracks generated during repeated charge/discharge processes arising from the anisotropy of the cell parameters;and electrolyte decomposition when traces of water are present. Regulating the surface nanostructure and bulk crystal lattice of electrode materials is an effective way to meet the demand for cathode materials with high energy density and outstanding stability. Surface modification treatment of positive active materials can slow side reactions and the lo

关 键 词：锂离子电池 高比能正极材料 表面限域掺杂 均匀包覆 稳定性 

分 类 号：O646[理学—物理化学]