摘要
高倍率磷酸铁锂电池的机理建模对电池设计与应用管理具有重要意义。针对当前机理模型存在全阶形式复杂度高、简化形式在高倍率下难拟合的问题,将简化的准二维(P2D)电化学模型与双状态热模型结合,建立电化学-热耦合简化机理模型,并通过参数辨识实现了模型在10~40C高倍率、宽范围下的实际放电曲线拟合。基于辨识后的模型,分析了电池高倍率放电下外部曲线变化趋势所反映的内部演化机理,发现高倍率放电初期电池端电压秒级的大幅度下降与液相锂离子浓度分布的不均匀性有关,放电中期的端电压回升来源于温度上升导致的电池内部各材料活性的不断增强。
Mechanism modeling of high C-rate LiFePO_(4) battery is very important to guide the design and application of battery.However,the full order mechanism model has high complexity,and the simplified form fits bad in high C-rate currently.To solve these problems,a simplified electrochemical thermal coupling mechanism model was established by combining the simplified pseudo-two-dimensions(P2D)electrochemical model with the two-state thermal model.Through parameter identification,the model can well fit the actual battery discharge curves in a wide range of 10~40C high rate.Based on the identified model,the internal evolution mechanism corresponding to the trend of external curves under high C-rate discharge was analyzed.The results show that:the seconds level sharp decrease of battery terminal voltage in the high C-rate discharge initial period is related to the heterogeneity of Li^(+) concentration distribution in the electrolyte phase,and the recovery of the terminal voltage in the intermediate period is due to the increasing activity of internal materials caused by the temperature rise.
作者
严康为
龙鑫林
鲁军勇
柳应全
吴羿廷
Yan Kangwei;Long Xinlin;Lu Junyong;Liu Yingquan;Wu Yiting(National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan 430033,China)
出处
《电工技术学报》
EI
CSCD
北大核心
2022年第3期599-609,共11页
Transactions of China Electrotechnical Society
基金
国家自然科学基金(51925704,51877214,51907203)
湖北省自然科学基金(2019CFB371,2019CFB373,2020CFB341)
中国博士后特别资助基金(2019T120972)资助项目。
关键词
高倍率
磷酸铁锂电池
机理模型
液相扩散
端电压回升
High C-rate
LiFePO_(4) battery
mechanism model
electrolyte phase diffusion
terminal voltage recovery
