(1. 湘潭大學(xué) 化學(xué)學(xué)院，湘潭 411105； 2. 湖南科技大學(xué) 化學(xué)化工學(xué)院，湘潭 411201)
摘 要: 通過碳熱還原法合成摻碳鋰離子電池正極材料單斜Li3V2(PO4)3，用XRD、SEM及電化學(xué)測(cè)試等方法對(duì)材料的結(jié)構(gòu)、形貌和電化學(xué)性能進(jìn)行表征和測(cè)試，探討石墨、乙炔黑以及蔗糖3種碳源對(duì)材料性能的影響，并分析不同碳源對(duì)材料性能影響的原因。結(jié)果表明，碳源的選擇對(duì)產(chǎn)物的結(jié)構(gòu)和電化學(xué)性能有很大的影響。以蔗糖為碳源制備的單斜Li3V2(PO4)3正極材料具有粒徑小、電荷轉(zhuǎn)移阻抗小等優(yōu)點(diǎn)，獲得了較好的電化學(xué)性能，當(dāng)電壓范圍為3.0~4.3和3.0~4.8 V時(shí)，其初始容量分別為127.8和166.2 mA∙h/g，30次循環(huán)后放電比容量分別為124.2和143.3 mA∙h/g。
關(guān)鍵字: Li3V2(PO4)3；正極材料；碳源
（1. School of Chemistry, Xiangtan University, Hunan 411105, China; 2. School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Hunan 411201, China）
Abstract:The carbon-doped monoclinic Li3V2(PO4)3 materials were synthesized by carbothermal reduction method. The crystal structures, morphologies and the electrochemical performances were characterized by XRD, SEM and electrochemical measurement. The effects of different carbon sources, such as graphite, acetylene black and sucrose, on the performance of as-synthesized cathode materials were investigated and the causes were also analyzed by impedance spectra and SEM. The results show that the carbon source exerts a significant influence on the structures and electrochemical properties of the materials. The material carbon-doped by sucrose has the best electrochemical performance due to smaller particles and lower charge-transfer resistance. In the voltage range of 3.0−4.3 and 3.0−4.8 V, the sample displays the initial capacity of 127.8 and 166.2 mA∙h/g, respectively, and after 30 cycles, the discharge capacities are 124.2 and 143.3 mA∙h/g, respectively.
Key words: Li3V2(PO4)3; cathode materials; carbon sources
