一款软包电池模组开发与应用

Development and application of a LFP pouch cell module

电池模组是电动汽车电池系统的关键组成部分,为电动汽车提供能量输出。本文推出了一款高能量密度高安全性的磷酸铁锂软包电池模组,指出提高体积利用率和成组效率是提高电池系统能量和整车续驶里程的关键路径之一。对于如何提高体积利用率和成组效率,分别从电池模组外部和电池模组内部两种途径进行了具体阐述。从电池模组外部分析,综合主流整车厂开发的电池包的包络,充分利用电池包络空间布置电池模组,提出增加标准软包电池模组高度的方案。在电池模组内部,利用数学理论公式对电池模组尺寸进行尺寸链分析,得出最大的软包电芯包络尺寸。通过增大软包电芯尺寸,提高软包电芯在电池模组中的体积利用率,达到提高成组效率和增加电池模组容量的效果。同时,对轻量化设计的电池模组进行有限元仿真。仿真强度满足要求后,进行振动和冲击等安全可靠性实验验证,确保电池模组的高安全性。综上,在磷酸铁锂软包电芯能量密度一定的前提下,实现了软包电池模组高能量密度和高安全性的目标,为后续推广应用奠定了基础。

The cell module is the key component of an electric vehicle battery system,providing the energy output for the vehicle.In this study,we describe a lithium iron phosphate(LFP)pouch cell module with high energy density and high safety factor.The basis for improving battery system effectiveness and vehicle driving range lies in enhancing volume utilization and group efficiency.To improve volume utilization and bunching efficiency,we investigated the cell module in detail,both internally and externally.From an external perspective,we considered integration with the battery pack envelopes developed by mainstream vehicle manufacturers.From this analysis,we suggest configurations of cell modules to optimize the utilization of battery envelope space and propose a scheme for increasing the height of standard LFP pouch cell modules.We obtained the maximum pouch cell envelope size using theoretical mathematical formulas.Increasing the pouch cell size allows improved volume utilization in the cell modules,with corresponding increases in bunching efficiency and cell module capacity.We then simulated the lightweight cell module by finite element modeling.Once the simulated strength met the stipulated requirements,reliability experiments(e.g.,for vibration and impact)were conducted to assess the safety performance of the cell module.Our conclusions are that the goals of high energy density and high safety can both be achieved,assuming a certain energy density.These findings lay the foundation for future popularization and practical application of LFP pouch cells.