中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2014年
2期
468-475
,共8页
吕凡%伍凌%管淼%钟胜奎%刘洁群
呂凡%伍凌%管淼%鐘勝奎%劉潔群
려범%오릉%관묘%종성규%류길군
正极材料%磷酸铁锂%Al3+掺杂%球磨%常温还原
正極材料%燐痠鐵鋰%Al3+摻雜%毬磨%常溫還原
정겁재료%린산철리%Al3+참잡%구마%상온환원
cathode material%lithium iron phosphate%Al3+doping%ball milling%room temperature reduction
采用共沉淀法制备掺Al3+前驱体FePO4?2H2O,并以乙二酸为还原剂,与Li2CO3反应在常温下球磨合成LiFePO4前驱混合物,后经热处理得到橄榄石型LiFe1-3y/2AlyPO4。用XRD、SEM、HRTEM和恒流充放电等对样品进行表征。结果表明:适量 Al3+掺杂不会破坏 LiFePO4的晶体结构,当掺杂量较低时(y=0.01),Al3+优先占据Fe位;当掺杂量较高时(y≥0.02),Al3+同时占据Li位和Fe位。电化学测试表明:LiFe0.985Al0.01PO4拥有最优的电化学性能,该样品在0.1C、1C和2C倍率下的首次放电比容量分别为162.4、152.2和142.0 mA?h/g,在1C倍率下循环100次后的放电比容量高达149.7 mA?h/g。
採用共沉澱法製備摻Al3+前驅體FePO4?2H2O,併以乙二痠為還原劑,與Li2CO3反應在常溫下毬磨閤成LiFePO4前驅混閤物,後經熱處理得到橄欖石型LiFe1-3y/2AlyPO4。用XRD、SEM、HRTEM和恆流充放電等對樣品進行錶徵。結果錶明:適量 Al3+摻雜不會破壞 LiFePO4的晶體結構,噹摻雜量較低時(y=0.01),Al3+優先佔據Fe位;噹摻雜量較高時(y≥0.02),Al3+同時佔據Li位和Fe位。電化學測試錶明:LiFe0.985Al0.01PO4擁有最優的電化學性能,該樣品在0.1C、1C和2C倍率下的首次放電比容量分彆為162.4、152.2和142.0 mA?h/g,在1C倍率下循環100次後的放電比容量高達149.7 mA?h/g。
채용공침정법제비참Al3+전구체FePO4?2H2O,병이을이산위환원제,여Li2CO3반응재상온하구마합성LiFePO4전구혼합물,후경열처리득도감람석형LiFe1-3y/2AlyPO4。용XRD、SEM、HRTEM화항류충방전등대양품진행표정。결과표명:괄량 Al3+참잡불회파배 LiFePO4적정체결구,당참잡량교저시(y=0.01),Al3+우선점거Fe위;당참잡량교고시(y≥0.02),Al3+동시점거Li위화Fe위。전화학측시표명:LiFe0.985Al0.01PO4옹유최우적전화학성능,해양품재0.1C、1C화2C배솔하적수차방전비용량분별위162.4、152.2화142.0 mA?h/g,재1C배솔하순배100차후적방전비용량고체149.7 mA?h/g。
Al3+-doped precursors (FePO4?2H2O) were prepared via a co-precipitation method. LiFePO4 precursor- mixtures were obtained by ball milling at room temperature using FePO4?2H2O, Li2CO3 and oxalic acid as raw materials, and then olivine-type LiFe1-3y/2AlyPO4 were synthesized by the following heat treatment. The samples were characterized by using X-ray diffraction, scanning electron microscope, high resolution transmission electron microscope and galvanostatic charge/discharge test. The results show that a proper amount of Al doping does not obviously change the structure of LiFePO4. When y=0.01, Al3+ions tend to occupy Fe site, and when y≥0.02, Al3+ions occupy both Fe and Li sites. LiFe0.985Al0.01PO4 exhibits the most impressive electrochemical performance as follows: its initial discharge capacities are 162.4, 152.2 and 142.0 mA?h/g at 0.1C, 1C and 2C rates, respectively, its discharge capacity is 149.7 mA?h/g even after 100 cycles at 1C rate.