Abstract: To address the trade-offs between energy density, thermal safety, and system cost in compact electric passenger cars, this paper proposes a system design method based on multidimensional performance balancing, and designs and implements a highly integrated energy storage device for the drive system. This device is based on high-energy-density ternary lithium-ion cells, employing a modular structure and laser welding technology to achieve low-resistance connections between battery modules. Through a layered insulation structure and a multi-sensor monitoring network, the thermal runaway warning response time is reduced to less than 2 s. Combining finite element analysis and topology optimization methods, the topology-optimized aluminum alloy housing achieves a 12.3% weight reduction, and the liquid cooling system controls the module temperature difference to within 3 ℃. Real-world vehicle verification shows that the system maintains good stability at 45 ℃, achieving a capacity retention rate of 95.3% after 200 cycles, with the vehicle completing the cycle without any failures. This paper systematically elucidates the design principles and optimization path, providing a theoretical basis and reusable engineering path for the design of high-performance battery systems for compact electric vehicles.

Key words: compact electric passenger cars; power battery system; energy density; thermal management technology; battery management system

摘要： 针对紧凑型电动乘用车在能量密度、热安全性与系统成本间的矛盾，文章提出一种基 于多维性能平衡的系统设计方法，设计并实现了一种高度集成的驱动系统能量存储装置。该 装置以高能量密度三元锂离子电芯为基础，采用模块化结构与激光焊接工艺，实现电池模组 低阻连接；通过分层绝缘结构与多传感器监测网络，热失控预警响应时间缩短至 2 s 以内。结 合有限元分析与拓扑优化方法，经拓扑优化的铝合金箱体实现 12.3%减重，并结合液冷系统 将模组温差控制在 3 ℃以内。实车验证表明，该系统在 45 ℃环境下仍具有良好稳定性，循 环 200 次后容量保持率达 95.3%，车辆以零故障完赛。文章系统阐述了设计原理与优化路径， 为紧凑型电动车高性能电池系统设计提供了理论依据与可复用的工程路径。

关键词: 紧凑型电动乘用车；动力电池系统；能量密度；热管理技术；电池管理系统