(1. 湘潭大學(xué) 化學(xué)學(xué)院 電化學(xué)能源儲存與轉(zhuǎn)換湖南省重點(diǎn)實(shí)驗(yàn)室,湘潭 411105;
2. 湘潭大學(xué) 化學(xué)學(xué)院 新能源裝備及儲能材料與器件國家國際科技合作基地,湘潭 411105)
摘 要: 采用溶膠-凝膠法合成鋰離子電池正極材料Li2FeSiO4/C,研究煅燒溫度對材料結(jié)構(gòu)和電化學(xué)性能的影響。通過X射線衍射(XRD)、掃描電鏡(SEM)、電化學(xué)阻抗測試(EIS)和充放電測試等方法對不同煅燒溫度下合成的Li2FeSiO4/C材料的結(jié)構(gòu)、表觀形貌及電化學(xué)性能進(jìn)行表征。結(jié)果表明:在650 ℃下合成的Li2FeSiO4/C具有良好的電化學(xué)性能,0.1C倍率下的首次放電比容量達(dá)到159.1 (mA?h)/g,50次循環(huán)后容量保持率高達(dá)92.1%。
關(guān)鍵字: Li2FeSiO4/C;正極材料;鋰離子電池;溶膠-凝膠法
(1. Hunan Province Key Laboratory of Electrochemical Energy Storage and Conversion, School of Chemistry, Xiangtan University, Xiangtan 411105, China;
2. National Base for International Science and Technology Cooperation, School of Chemistry, Xiangtan University, Xiangtan 411105, China)
Abstract:The Li2FeSiO4/C composite cathode material was synthesized by sol-gel method, and the influences of sintering temperatures on the electrochemical properties of Li2FeSiO4/C were examined. The structure, morphology and electrochemical performance of Li2FeSiO4/C composites sintered at various temperatures were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and charge-discharge tests. The results reveal that the sample sintered at 650 ℃ can deliver the highest reversible capacity of 159.1 (mA?h)/g at rate of 0.1C, with excellent capacity retention of 92.1% after 50 cycles among all the samples.
Key words: Li2FeSiO4/C; cathode material; lithium-ion battery; sol-gel method


