摘要
通过分析浸润、极化和材料活化等影响因素,研究磷酸铁锂(LiFePO4)锂离子电池常温循环容量抬升异常问题。改善电解液浸润将电池循环容量抬升从7.57%降低至6.02%,仍是异常高抬升,证明浸润影响不是主因;原位电化学阻抗谱(EIS)结果表明,扩散阻抗(W0)对循环容量抬升影响较大,电池在2.00~3.65 V充放电,1.00 C循环60次后,W0从116.16 mΩ减小至96.66 mΩ,循环容量抬升5.96%;而0.20 C循环无容量抬升,W_(0)亦无降低趋势。电极材料活化是造成循环容量抬升的关键,若材料活化充分、容量发挥正常,抬升比可控制在2%以内。
The abnormal cycle capacity increase of lithium iron phosphate(LiFePO4)Li-ion battery at room temperature was studied by analyzing the influencing factors such as infiltration,polarization and material activation.The improving of infiltration reduced cycle capacity increase from 7.57%to 6.02%,was still an abnormally high increase,which proved that the influence of infiltration was not the main reason.The in-situ electrochemical impedance spectroscopy(EIS)results showed that the reduction of diffusion impedance(W0)had a great influence on the cycle capacity increase.When charged-discharged in 2.00-3.65 V,after 60 cycles at 1.00 C,the diffusion resistance decreased from 116.16 mΩto 96.66 mΩ,the cycle capacity was increased by 5.96%,while the 0.20 C cycle capacity had no increase and W0 had no reduction.The material activation was the key reason for the cycle capacity increase.When the material was fully activated and utilized,the cycle capacity increase could be controlled within 2%.
作者
段锐
郑刚
钟明明
鲁劲华
DUAN Rui;ZHENG Gang;ZHONG Ming-ming;LU Jin-hua(Hefei Gotion High-Tech Power Energy Co.,Ltd.,Hefei,Anhui 230011,China)
出处
《电池》
CAS
北大核心
2021年第5期490-493,共4页
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