高性能18650型锂离子电池倍率和低温电化学性能的评估及研究

Evaluation and research on the high performance 18650 type lithium batteries of rate and low temperature electrochemical performance

本文采用高镍三元层状LiNi_(0.5)Co_(0.2)Mn(0.3)O_2材料作为正极材料、中间相炭微球作为负极材料制备了18650型锂离子成品电池。电化学性能表明,该锂离子电池具有优异的高倍率特性和低温循环性能。常温测试环境中,电池在3C大电流充放电及2.0-4.2 V工作电位条件下(1C=1553.8mA/g),1000次循环后实际容量保持在80%以上。尤其是低温-20℃测试温度下,采用0.33C充电和1C放电,电池循环100周后的容量保持率高达99.8%,表现出优异的低温循环稳定性能。

The 18650-typelithiumion battery has been fabricated by using ternary Ni-rich layered LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2 as cathode material and mesocarbon microbeads(MCMB)as anode material,which demonstrates excellent high-rate and low-temperatureperformances.The full battery can retain specific capacity higher than 80% at a high 3Crate in a voltage range of 2.0-4.2Vafter1000 electrochemical cycles at room temperature(1C=1553.8mA/g).It is notable that such a battery reveals negligible capacity decay(~99.8%)when cycled at-20℃ by using 0.33 Ccharge and 1Cdischarge processes,indicating itsexcellent electrochemical performances at lowtemperature.