储能用锂离子电池充放电能量效率的影响因素  

Influence factors of charge-discharge energy efficiency of Li-ion battery for energy storage

作　　者：于维珂 汪涛 杨尘 YU Wei-ke;WANG Tao;YANG Chen(Shanghai Electric Guoxuan New Energy Technology Co.,Ltd.,Shanghai 200041,China)

机构地区：[1]上海电气国轩新能源科技有限公司,上海200041

出　　处：《电池》2020年第6期552-555,共4页Battery Bimonthly

摘　　要：研究储能用磷酸铁锂(LiFePO 4)正极锂离子电池充放电能量效率(η)的影响因素。采用恒功率充放电时,η较恒流充放电高出1.02%。在1 h率(P 1)恒功率充放电条件下,最佳荷电状态(SOC)区间为10%~90%,且η保持在93%以上。η与温度呈正相关,最优温度区间为25~30℃。倍率升高会加剧电池极化,与η呈负相关的趋势。在45℃下,P 1恒功率充放电时,η的变化规律呈现3个阶段特征:循环初期,由于极化较轻,η基本稳定;在放电能量保持率的平缓衰减期,由于电池极化增加,η缓慢衰减;循环末期,随着极化进一步加剧,放电能量保持率出现加速衰减趋势,此时也造成η快速降低。The charge-discharge energy efficiency(η)of lithium iron phosphate(LiFePO 4)cathode Li-ion battery for energy storage was studied.Theηthat obtained at constant power charge-discharge method was 1.02%higher than at galvanostatic charge-discharge method.Theηat 1 h rate(P 1)constant power charge-discharge was 93%,10%-90%was the best state of charge(SOC)range.Theηwas positively correlated with the temperature,the best temperature range was 25-30℃.The increase of multiplier aggravated the polarization of the battery,so theηpresented a negative growth trend.At 45℃,theηat P 1 constant power cycle showed three phases.The trend ofηwas generally stable at the beginning of the cycle due to small polarization.Then during the gentle attenuation period of discharge energy retention rate,theηalso decreased slowly due to the increase of battery polarization.Finally,the polarization increased rapidly until the end of the cycle when the discharge energy retention rate accelerated,resulting in a rapid decrease inη.

关 键 词：储能 磷酸铁锂(LiFePO 4) 锂离子电池 能量效率 恒流 恒功率 

分 类 号：TM912.9[电气工程—电力电子与电力传动]