摘要
钠离子电池因其原材料储量丰富、成本低、安全环保等优势在大规模储能、低速电动车领域具有广阔的应用前景。氟磷酸钒钠[Na_(3)V_(2)(PO_(4))_(2)F_(3),NVPF]正极材料具有稳定的三维框架结构、高的理论比容量(128 mA·h/g)和高的工作电压(约3.8 V)等优点,已成为近年来钠离子电池正极材料研究的热点。然而,NVPF较低的电子电导率和较慢的离子扩散速率导致其实际比容量偏低且倍率性能不理想,阻碍了其进一步发展。为此,研究者们通过优化NVPF的合成工艺,并采用包覆、离子掺杂和结构设计等方法对其进行改性,使其电化学性能得到了显著提升,极大增强了NVPF在钠离子电池中的应用潜力。本文通过对近年相关文献的回顾,介绍了NVPF的晶胞特征,并梳理了NVPF的四种脱嵌钠机制(固溶反应机制、分步钠脱嵌机制、三步钠脱嵌机制和两步钠脱嵌机制);简要综述了NVPF常用的三种合成方法(高温固相法、水热法和溶胶-凝胶法),并归纳了各方法的优缺点;详细介绍了利用包覆、离子掺杂和结构设计等方法改性NVPF的研究进展。最后,从实际应用角度出发,对NVPF的合成、改性及其全电池的发展进行了展望,以期推动NVPF正极材料在钠离子电池中的应用化进程。
Sodium-ion batteries have substantial potential in large-scale energy storage and low-speed electric vehicles owing to their raw material abundance,low cost,safety,and relatively low environmental impact.Recently,sodium vanadium fluorophosphate[Na_(3)V_(2)(PO_(4))_(2)F_(3),NVPF]has become a focus of research into cathode materials for sodium-ion batteries.Key attributes of NVPF are its stable three-dimensional framework structure,high theoretical capacity(128 mA·h/g),and high working voltage(approximately 3.8 V).However,low electronic conductivity and slow ion diffusion rate resulted in both low actual capacity and unsatisfactory rate performance,which had hindered further development.Therefore,researchers have been able to considerably improve electrochemical performance by optimizing the synthesis process,coating,ion doping,and structural design.Together,these improvements have greatly enhanced the potential for application of NVPF in sodium-ion batteries.Based on a review of recent relevant literature,this paper first introduces the cell characteristics of NVPF.Next,it investigates four Na+extraction/insertion mechanisms(i.e.,the solid solution reaction,step-by-step Na+extraction/insertion,three-step Na+extraction/insertion,and two-step Na+extraction/insertion mechanisms).It also briefly summarizes three common synthesis methods(i.e.,the high temperature solid-state,hydrothermal,and sol-gel methods)and their advantages and disadvantages.Then,recent progress with enhanced NVPF(modified by coating,ion doping,and optimized structural design)is described in detail.Finally,the practical development of the synthesis and modification of NVPF cathode materials and the NVPF full cell are explored in the context of future real-world applications of NVPF in sodium-ion batteries.
作者
孙畅
邓泽荣
江宁波
张露露
FANG Hui
杨学林
SUN Chang;DENG Zerong;JIANG Ningbo;ZHANG Lulu;FANG Hui;YANG Xuelin(College of Electrical Engineering&New Energy,Hubei Provincial Collaborative Innovation Center for New Energy Microgrid,China Three Gorges University,Yichang 443002,Hubei,China;College of Materials and Chemical Engineering,China Three Gorges University,Yichang 443002,Hubei,China;Department of Physics,Sam Houston State University,Huntsville,Texas 77341,USA)
出处
《储能科学与技术》
CAS
CSCD
北大核心
2022年第4期1184-1200,共17页
Energy Storage Science and Technology
基金
国家自然科学基金(52072217,22179071,51772169)
国家重点研发计划(2018YFB0905400)
湖北省技术创新专项重大项目(2019AAA164)。
关键词
钠离子电池
正极材料
氟磷酸钒钠
制备
改性
sodium-ion batteries
cathode materials
sodium vanadium fluorophosphate
preparation
modification
