摘要
利用电化学阻抗谱技术(EIS)结合弛豫时间分布技术(DRT)研究了25、55和70℃下LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)的日历时效过程。分别引入正、负极半电池和正、负极对称电池,研究正、负极对全电池阻抗的贡献,DRT辅助解析了EIS在10^(-1)~10^(4) Hz频率范围的不同时间常数的物理化学意义,建立并拟合等效电路模型(ECM)。结果显示,固态电解质界面膜(SEI)产生的阻抗是电池容量衰减的主要来源。利用FT-IR和XPS研究了正、负极的老化特征,采用扫描电镜观察正、负极表面和横截面在加速日历失效过程中的形貌变化。结果表明,负极产生的阻抗是电池性能下降的主要来源。
The study of 100%state of charge(SOC)LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2) battery at 25,55,70℃during 210 d storage was investigated by using electrochemical impedance spectroscopy(EIS)combining distribution of relaxation time technique(DRT).The half cells and symmetrical cells of both cathode and anode were made to distinguish the impedance contribution.The impedance of solid electrolyte interphase(SEI)was the most contribution of the 100%SOC NCA battery.The change of resistance in 10^(-1)~10^(4) Hz were highlighted and the time constants meaning of each was systematically analyzed.Equivalent circuit model(ECM)was established and EIS data was fitted.The different aging degree of anode and cathode were characterized by using FT-IR and XPS.The surface morphology of cathode and anode as well as the cross section were observed by SEM.Results show that the aging of anode is more severely than cathode.
作者
刘薇
程广玉
曹永杰
王宁
张俊喜
LIU Wei;CHENG Guangyu;CAO Yongjie;WANG Ning;ZHANG Junxi(Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power,Shanghai University of Electric Power,Shanghai 200090,China;State Key Laboratory of Space Power Technology,Shanghai Institute of Space Power Sources,Shanghai 200245,China;Department of Chemistry,Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials,Institute of New Energy,Fudan University,Shanghai 200438,China)
出处
《电源技术》
CAS
北大核心
2022年第7期748-753,共6页
Chinese Journal of Power Sources
关键词
日历老化
寿命预测
电化学阻抗谱
弛豫时间分布
事后分析
calendar aging
lifetime prediction
electrochemical impedance spectroscopy
distribution of relaxation times
post-mortem analysis
