(1. 合肥工業(yè)大學 化工學院，合肥 230009；
2. 可控化學與材料化工安徽省重點實驗室，合肥 230009)
摘 要: 采用X射線衍射(XRD)、透射電鏡(TEM)和電化學方法，研究Ni2+摻雜對正極材料Li3V2(PO4)3的結構、形貌和電化學性能的影響。結果表明：摻雜適量的Ni2+不會改變Li3V2(PO4)3的單斜晶系結構，但可提高材料的電導率，抑制電池在充放電過程的極化。在室溫下，Li3(Ni0.05V0.95)2(PO4)3以0.1C倍率放電的初始比容量為115 mA·h/g，放電倍率從0.1C增加到0.4C循環(huán)60次后，比容量衰減率僅為2.7%，而未摻雜原樣Li3V2(PO4)3的初始比容量為129 mA·h/g，60次循環(huán)后比容量衰減率約為30.3%；當放電倍率增至1C時，80次循環(huán)后，Li3(Ni0.05V0.95)2(PO4)3比容量為99.8 mA·h/g，而原樣的比容量為84.1 mA·h/g；當放電倍率增至5C時，循環(huán)120次后，Li3(Ni0.05V0.95)2(PO4)3比容量為67.7 mA·h/g，而原樣的比容量降為0。循環(huán)伏安和交流阻抗測試表明，Li3(Ni0.05V0.95)2(PO4)3的可逆性明顯優(yōu)于Li3V2(PO4)3的可逆性。
關鍵字: 鋰離子電池；Ni2+；Li3V2(PO4)3；摻雜；電化學性能
（1. School of Chemical Engineering, Hefei University of Technology, Hefei 230009, China;
2. Anhui Key Laboratory of Controllable Chemical Reaction & Material Chemical Engineering,
Hefei 230009, China）
Abstract:The effects of Ni2+ doping on the structure, morphology and electrochemical performance of cathode material Li3V2(PO4)3 were studied by X-ray diffractometry(XRD), transmission electron microscopy(TEM) and electrochemical method. The results indicate that the monoclinic structure of Li3V2(PO4)3 is not changed while the conductivity increases and the polarization of the battery is restrained during charge-discharge process due to doping appropriate amount of Ni2+. Li3(Ni0.05V0.95)2(PO4)3 has an initial specific capacity of 115 mA·h/g at 0.1C discharging at room temperature and the specific capacity only decreases by 2.7% after 60 cycles when the discharging rate changes from 0.1C to 0.4C. However, the raw sample Li3V2(PO4)3 has an initial specific capacity of 129 mA·h/g and the specific capacity decreases by 30.3% after 60 cycles. Furthermore, when the discharging rate increases to 1C, the specific capacity of Li3(Ni0.05- V0.95)2(PO4)3 decrease slightly to 99.8 mA·h/g after 80 cycles, while the specific capacity of the raw sample declines considerably to 84.1 mA·h/g. When the discharging rate increases to 5C, the specific capacity of Li3(Ni0.05V0.95)2(PO4)3 decreases to 67.7 mA·h/g after 120 cycles, while the specific capacity of the raw sample declines to 0. Additionally, the tests of cyclic voltammogram and AC impedance show that the reversibility of Li3(Ni0.05V0.95)2(PO4)3 is obviously better than that of Li3V2(PO4)3.
Key words: Li-ion battery; Ni2+; Li3V2(PO4)3; doping; electrochemical performance
