LiFePO4的软化学合成及锂快离子导体修饰
Soft Chemistry Synthesis and Lithium Fast Ionic Conductor Modification for LiFePO4 Cathode Material of Li-Ion Battery
作者单位E-mail
闫时建 太原科技大学材料科学与工程学院, 先进材料研究所, 太原 030024  
高亮 太原科技大学材料科学与工程学院, 先进材料研究所, 太原 030024  
张敏刚 太原科技大学材料科学与工程学院, 先进材料研究所, 太原 030024 am_lab@yeah.net 
郑建军 太原科技大学材料科学与工程学院, 先进材料研究所, 太原 030024  
刘建生 太原科技大学材料科学与工程学院, 先进材料研究所, 太原 030024  
摘要: 采用溶剂热法制备正极材料LiFePO4,采用溶胶凝胶法制备Li0.5La0.5TiO3(LLTO)粉体,并通过酒精悬浮法对LiFePO4进行修饰,修饰量为LiFePO4质量的1%~4%,获得了薄壁蜂窝状自组装结构的LiFePO4上修饰有球状LLTO纳米颗粒的复合正极材料。通过进行充放电测试、交流阻抗测试及循环伏安测试,研究了不同修饰量对电池的充放电比容量、循环性能及可逆性的影响,发现当LLTO含量为3%(w/w)时,以2C和5C倍率放电相对于没有修饰LLTO的LiFePO4的比容量分别提高29.7%和31.6%,30次循环之后,容量损失率较未改性前减小4.13%,循环伏安曲线上氧化还原峰之间的电位差仅为0.117 V,以3%的LLTO修饰改性的LiFePO4显著提高了电池的倍率性能、循环性能和低温性能。
关键词: 锂离子电池  LiFePO4  Li0.5La0.5TiO3  修饰
基金项目: 山西省科技基础条件平台建设(No.2015091011)、山西省重点学科建设经费、晋城市科技计划(No.201501004-21)和太原市科技计划(No.110153)资助项目。
Abstract: Soft chemistry synthesis and electrochemical properties via Li0.5La0.5TiO3 (LLTO) fast ionic conductor modification for LiFePO4 cathode material of Li-ion battery were investigated. LiFePO4 was synthesized via solvothermal method, LLTO powder was synthesized via sol-gel method, LiFePO4 was modified by LLTO with the proportion of 1%~4%(w/w) via alcohol suspension mixing method, and the composite cathode materials of thin-wall cellular characteristic self-assembly LiFePO4 modified by spherical LLTO nano-particles were acquired. The effects of LLTO modified proportion on charge and discharge specific capacity, cycle performance and reversibility were studied by charge/discharge test, AC impedance test and cyclic voltammetry test. The results indicate when LLTO modified proportion is 3% (w/w), the discharge specific capacity increases by 29.7% in the current rate of 2C and increases by 31.6% in the current rate of 5C, the capacity loss rate after 30 charge/discharge cycles decreases by 4.13% compared to unmodified condition, and the potential difference between redox peaks in cyclic voltammetry curve is only 0.117 V. LiFePO4 modified by LLTO with proportion of 3% significantly improves the current rate capability and cycle performance of Li-ion battery, and also improves the low temperature performance.
Keywords: Li-ion battery  LiFePO4  Li0.5La0.5TiO3  modification
投稿时间:2018-02-07 修订日期:2018-05-04
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闫时建,高亮,张敏刚,郑建军,刘建生.LiFePO4的软化学合成及锂快离子导体修饰[J].无机化学学报,2018,34(7):1319-1326.
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