(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用高能球磨結(jié)合微波合成工藝，以Li2CO3、FeC2O4∙2H2O、納米SiO2和葡萄糖為原料合成鋰離子電池正極材料Li2FeSiO4/C。利用X射線衍射(XRD)、掃描電鏡(SEM)和恒電流充放電測試等方法對該材料的結(jié)構(gòu)、表觀形貌及電化學(xué)性能進(jìn)行表征。考察超導(dǎo)電碳黑的添加、微波處理時(shí)間以及微波加熱溫度等對Li2FeSiO4/C材料合成及其性能的影響。結(jié)果表明：以超導(dǎo)電碳黑為微波耦合劑，采用微波合成法在650 ℃下處理10 min可快速制備具有正交結(jié)構(gòu)的Li2FeSiO4/C材料；獲得的Li2FeSiO4/C材料顆粒細(xì)小均勻，具有較好的電化學(xué)性能；在60 ℃下以C/20對Li2FeSiO4/C材料進(jìn)行充放電時(shí)，其首次放電容量為121.7 mA∙h/g，10次循環(huán)后其放電容量仍保持為119.2 mA∙h/g。
關(guān)鍵字: Li2FeSiO4/C；鋰離子電池；正極材料；微波合成
cathode materials for lithium ion battery
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:A novel synthetic method of ball milling and microwave synthesis was applied to synthesize Li2FeSiO4/C cathode materials using Li2CO3, FeC2O4∙2H2O-SiO2 and sluwse as the raw material. The prepared samples were characterized by XRD, SEM, and galvanostatic charge-discharge test. The influences of addition of carbon powder, microwave irration time and irration temperature on the synthesis and properties of Li2FeSiO4/C materials were examined. The results show that, using super-P carbon as microwave absorber powder, with Li2FeSiO4/C olivine-phase material can be quickly synthesized by microwave processing at 650 ℃ for 10 min. The obtained materials exhibit uniform and fine particle sizes all has good electrochemical properties. The initial discharge capacity of the prepared Li2FeSiO4/C material is 121.7mA∙h/g at 60 ℃, after 10 cycles, the discharge capacity maintains 119.2 mA∙h/g.
Key words: Li2FeSiO4/C; Li-ion battery; cathode material; microwave synthesis
