Development of Thermal Sprayed Battery Cell Terminal Electrical Interconnection.

汽车锂离子电池组具有高能量密度、低自放电和便携性等特点，使其成为电动、混合动力或插电式混合动力汽车中不可缺少的电源。汽车电池组由大量电连接的独立电池组成。制造所需的电气接头是几个挑战，包括高导电性和不同材料的焊接，用相对较厚的母线连接箔片，以及连接多个板材。电池的连接有两个部分：翼片到翼片连接和翼片到母线连接。后者最难实现，因为它假定连接不同厚度和不同物理特性的不同材料(通常是铝片和铜母线)。这类接头的主要电气要求是具有低电阻，因为在接头处较低的电阻会导致低能量损失、低发热量以及随后较低的接头温度在充电和放电期间增加。使用直流逆变器闭环和电容放电电源，电阻点焊(RSW)是连接各种类型和大小电池的最具成本效益和最快速的方法。然而，由于铝铜金属间化合物(IMCs)的形成，直接应用于铝接头和铜母线的连接是困难的，该项目的总体目标是开发基于RSW的形成电互连界面的工艺，该工艺不含金属间化合物，电池电极与母线之间的接触电阻低。开发的工艺还应允许与合作伙伴加拿大福特汽车公司和福特汽车公司以及温莎大学和罗曼·梅夫博士合作制造可扩展的电池单元到模块系统。罗曼·格罗曼温莎大学Maev电子邮件：maev@uwinsor.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