钠离子电池正极材料磷酸钒钠的碳包裹制备及钛掺杂改性研究  

The Modified Electrochemical Performance of Sodium Vanadate Phosphate through Carbon Coating and Titanium Doping

作　　者：李家宝 李子茜 王若星 唐绍聪 郝静静 王赪胤[1] 潘丽坤[2] LI Jiabao;LI Ziqian;WANG Ruoxing;TANG Shaocong;HAO Jingjing;WANG Chengyin;PAN Likun(School of Chemistry and Chemical Engineering,Yangzhou University,Yangzhou 252059,China;School of Physics and Electronic Science,East China Normal University,Shanghai 200062,China)

机构地区：[1]扬州大学化学化工学院,江苏扬州225002 [2]华东师范大学物理与电子科学学院,上海200062

出　　处：《聊城大学学报（自然科学版）》2023年第2期17-24,52,共9页Journal of Liaocheng University:Natural Science Edition

基　　金：国家自然科学基金项目(21978251)资助。

摘　　要：磷酸钒钠(Na_(3)V_(2)(PO_(4))_(3),简写为NVP)具有钠离子快速导体结构,被认为是很有前景的钠离子电池正极材料。但是NVP的低电子导电性以及循环过程中大的结构变化阻碍了其商业化应用进程。通过在NVP中引入导电碳载体以及进行微量的钛掺杂,显著提升了其电子和离子导电性。碳载体可以改善其电子导电性,同时为其体积变化提供了有效的缓冲;而微量钛掺杂一方面可以提升晶体结构的稳定性,同时加快了离子扩散和传输。碳包裹和钛掺杂的协同效应极大地改善了磷酸钒钠正极的电化学性能,在恒电流充放电测试中,0.1 A·g^(-1)电流密度下循环100周后,其可逆容量可以达到111.7 mA·h·g^(-1);在倍率测试中,在10.0 A·g^(-1)电流密度下,可逆容量可以达到85.3 mA·h·g^(-1)。Due to the unique structure with fast Na+diffusion pathways,sodium vanadate phosphate(Na_(3)V_(2)(PO_(4))_(3),NVP)has been considered as one of the most promising cathodes for sodium-ion batteries.However,its poor electronic conductivity and huge structure change upon cycling restrict the further development of NVP for practical applications.Herein,a dual strategy,including carbon coating and simultaneous titanium(Ti)doping,have been developed for the modification of NVP cathode.Specifically,the introduction of carbonaceous agent dramatically improved the electronic conductivity and provided efficient buffering matrixes for the hybrid to mitigate the structure change upon cycling;meanwhile,partial Ti dopingenhanced the stability of crystal structure and accelerated ionic diffusion kinetics.In general,the synergistic coupling between carbon coating and Ti doping greatly improved the electrochemical performance of target NVP cathode.Consequently,the galvanostatic charge/discharge test demonstrates a reversible capacity of 111.7 mA·h·g^(-1)after 100 cycles at 0.1 A·g^(-1),and a reversible capacity of 85.3 mA·h·g^(-1)can still be obtained at 10.0 A·g^(-1)upon the rate test.

关 键 词：钠离子电池 磷酸钒钠 碳包裹 钛掺杂 电化学性能 

分 类 号：TQ136.1[化学工程—无机化工]