引用本文:
钟胜奎, 尹周澜, 王志兴, 陈启元. 锂离子电池正极材料LiVPO4F的制备及性能[J]. 应用化学,
2007, 24(3): 278-281.
Citation: ZHONG Sheng-Kui, YIN Zhou-Lan, WANG Zhi-Xing, CHEN Qi-Yuan. Preparation and Characterization of LiVPO4F for Cathode Material for Lithium-ion Batteries[J]. Chinese Journal of Applied Chemistry, 2007, 24(3): 278-281.
Citation: ZHONG Sheng-Kui, YIN Zhou-Lan, WANG Zhi-Xing, CHEN Qi-Yuan. Preparation and Characterization of LiVPO4F for Cathode Material for Lithium-ion Batteries[J]. Chinese Journal of Applied Chemistry, 2007, 24(3): 278-281.
锂离子电池正极材料LiVPO4F的制备及性能
摘要:
利用碳热还原法,通过2步反应合成了LiVPO4F。首先五氧化二钒、磷酸二氢铵和高表面的碳在惰性气体的保护下合成中间体VPO4。然后VPO4和LiF进一步反应生成单相LiVPO4F。考察了不同反应温度对产物组成和电化学性能的影响。结果表明,随着焙烧温度的升高,杂相的衍射峰逐渐消失,当焙烧温度达750℃时,所得样品为纯相的LiVPO4F。XRD测试表明,所合成的LiVPO4F正极材料属于三斜晶系,与天然矿羟基锂铁磷石是同构的。其晶胞参数:a=0.5149nm,b=0.5292nm,c=0.7445nm,α=67.397°,β=67.518°,γ=82.008°,晶胞体积为0.1730nm3,属于P1空间群。SEM测试表明,其产品颗粒比较均匀,平均粒径为2μm左右;电化学测试表明,该材料在0.1C充放电下,首次充电容量为149mA·h/g,首次放电容量达130mA·h/g,放电平台在4.2V左右(vs.Li/Li+),循环50次后其容量为111mA·h/g。
English
Preparation and Characterization of LiVPO4F for Cathode Material for Lithium-ion Batteries
Abstract:
LiVPO4F was prepared with a two-step reaction method based on a carbothermal reduction(CTR) process. In the initial CTR step, V2O5, NH4H2PO4, and carbon with a high surface area reacted under an inert atmosphere to yield the trivalent vanadium phosphate, VPO4. In the second incorporation step, the CTR VPO4 reacted with LiF to yield the single phase LiVPO4F. The effect of reaction temperature on the structure and the electrochemical properties were investigated. The results show that the sample synthesized at 750℃ has a single phase LiVPO4F. XRD studies show that LiVPO4F synthesized has a triclinic structure(space group P1), isostructural with the naturally occurring mineral tavorite, LiFePO4·OH. The crystallographic parameters of the prepared LiVPO4F powders are as follows, a=0.514 9 nm, b=0.529 2 nm, c=0.744 5 nm, α=67.397°, β=67.518°, γ=82.008°, and cell volume=0.173 0 nm3. SEM image showed that the particle size was about 2 μm with homogenous distribution. Electrochemical test shows that the initial charge and discharge capacity were about 149 mA·h/g and 130 mA·h/g, respectively at a rate of 0.1C, with an average discharge voltage of 4.2 V(vs.Li/Li+), and the capacity retain 111 mA·h/g after 50 cycles.
-
Key words:
- lithium ion battery
- / cathode material
- / LiVPO4F
- / carbothermal reduction method
-
-
扫一扫看文章
计量
- PDF下载量: 1
- 文章访问数: 550
- HTML全文浏览量: 53
下载:
