Development of Thermal Sprayed Battery Cell Terminal Electrical Interconnection.

汽车锂离子电池组的高能量密度、低自放电和便携性特性使其成为广泛用于电动、混合动力或插电式混合动力电动汽车的不可或缺的电源。汽车电池组由大量电连接的单个电池组成。制造所需的电气接头代表了几个挑战，包括焊接高导电性和不同的材料，连接箔片与相对厚的母线，以及连接多个片材。电池的连接有两个部分：极耳到极耳的连接和极耳到汇流条的连接。后者是最难实现的，因为它假设连接不同厚度和不同物理特性的不同材料（通常是Al接头和Cu母线）。这种接头的主要电气要求是具有低电阻，因为接头处的较低电阻导致低能量损失、低热量产生，并且随后在充电和放电期间较低的接头温度增加。电阻点焊（RSW）是连接各种电池类型和尺寸的电池的最具成本效益和快速的方法，同时使用直流逆变器闭环和电容器放电电源。然而，直接应用RSW连接Al接头和Cu母线是困难的，因为形成Al-Cu金属间化合物（IMC），这是脆性的，具有高电阻。 该项目的总体目标是开发基于RSW的工艺，用于形成电气互连接口，该接口不含IMC，并且在电池电极和汇流条之间具有低接触电阻。 开发的工艺还应允许与加拿大合作伙伴福特汽车公司和福特汽车公司与温莎大学和Roman Maev博士合作制造可扩展的电池单元到模块系统。 Roman Gr. Maev，温莎大学，maev@uwindsor.ca

High energy density, low self-discharge, and portability characteristics of automotive Li-ion battery packs make them an indispensable power source that is broadly used in electric, hybrid or plug-in-hybrid electric vehicles. An automotive battery pack consists of a large number of individual cells that are electrically connected. Making the required electrical joints represents several challenges, including welding of highly conductive and dissimilar materials, connecting foil tabs with relatively thick bus bar, and joining of multiple sheets. The joining of cells has two parts: tab-to-tab joining and tab-to-bus bar joining. The latter is most difficult to implement since it assumes joining dissimilar materials (usually Al tabs and Cu bus bar) of different thicknesses and different physical characteristics. The main electrical requirement for such joints is to have low electrical resistance, since lower electrical resistance at the joint results in low energy loss, low heat generation and subsequently, lower joint temperature increases during charging and discharging. Resistance spot welding (RSW) is the most cost-effective and rapid method for joining cells for a wide range of battery types and sizes, using both direct current inverter closed loop and capacitor discharge power supplies. However, direct application of RSW to joining Al tabs and Cu bus bar is difficult because of forming Al-Cu intermetallic compounds (IMCs), which are brittle and have a high electrical resistance. The overall goal of the project is to develop the RSW-based process for forming an electrical interconnection interface, which is IMC free and has low contact resistance between battery electrodes and bus bar. The developed process should also allow for fabrication of scalable battery cell-to-module systems with the partner Ford Motor Company of Canada and Ford Motor Company in collaboration with the University of Windsor and Dr. Roman Maev. Roman Gr. Maev, University of Windsor, maev@uwindsor.ca