While most people know what components comprise a traditional gasoline-powered automobile engine, they likely know little about the components or parts of an Electric Vehicle (EV) battery pack. This is understandable because EVs are still relatively new in the automotive marketplace, and the conception of how exactly a battery works is more difficult to understand when compared with the myriad of moving components that comprise internal combustion engines.
In reality, EV battery packs possess many traditional machine components. EV battery pack manufacturing processes, in particular, rely heavily on a variety of machine components including MISUMI components which are present at every step in the fabrication process.
To grasp this process, it’s helpful to unpack some basic terminology first. The Battery Cell is a small, rectangular component roughly the geometry of a paperback book. These battery cells are assembled together in frames to form Battery Modules. These modules are then linked together via a myriad of electrical connections and enclosed in the Battery Pack which is assembled directly to the automobile frame. The following arrow diagram below is a compass to understand the process terminology.
Battery Cells -> Battery Modules -> Battery Pack
Battery Cells
Battery Modules
Battery Pack
The process outlined in this article will begin with taking the battery cells out of packaging. This article will discuss the fabrication process using the battery cells as the “raw material” in the battery pack fabrication process. These small individual cells are typically manufactured at other, specialized facilities and arrive at the automobile fabrication plant as completed products. This workflow is the vision for the vaulted Tesla Gigafactory in Nevada which will produce all the battery cells required for the Tesla’s automotive assembly facilities.
The individual battery cells are simply metallic cartridges that contain an anode, cathode, and separator immersed in an electrolyte fluid.
Lithium-Ion Battery Schematic
Before the cells can be assembled into modules, each cell undergoes checks within a specialized fixture. This process is essentially a “leak check” process to ensure that the electrolyte isn’t leaking from the cell and to ensure that no moisture intrusion occurs over the entire operational life of the battery. This step is vitally important to ensure that the cells are properly functioning, and future battery capacity won’t be compromised.
EV Battery Assembly Fixture
The machine components that unpack the battery cells from packaging are comprised of many components such as power cables, roller conveyors, rotary shafts, and linear ball bushings.
The fixtures that check the battery cells are also comprised of dozens of components such as aluminum extrusions, configurable mounting plates, timing belt/pulley systems, circular cordsets, and circular connectors.
The next step in the process involves assembling the battery cells into battery modules. Typically, there are about 12 battery cells per battery module, but this varies across automotive make and model. The modules stack within a metallic frame. This frame comprises the module housing and protects the cells from physical shock loads.
This assembly process is highly automated and involves many MISUMI configurable machine components. The most visible of these components are the timing and conveyor belts which run the workpieces through the process.
The last step in battery pack fabrication is assembling the modules into the battery pack housing. This step involves a significant number of electrical hookups and fine-tuning. For example, the Nissan Leaf EV contains 48 battery modules which are all connected together via electrical monitoring equipment. These modules are typically picked and placed by an automated robotic assembly arm into the battery pack housing. After all the modules are placed into the housing they are manually connected together by an automotive technician. After all connections have been made, the battery pack housing cover is placed manually; finally, an automated robot arm is typically used to drill all screws thus completing the battery pack fabrication process.
Nissan Leaf
Tennen-Gas, CC BY-SA 3.0, via Wikimedia Commons
The MISUMI components that are typically employed in this final step involve control and instrumentation cables, sensor cordsets, angle brackets, locating pins, shims and spacers, and pressure gauges.
From this step, the completed battery pack is ready to be assembled into the automotive frame. Indeed, each EV battery pack could not be fabricated without the critical manufacturing functions performed by dozens of machined components including MISUMI components. To see how MISUMI can help with your EV application, check out our dedicated page here.
Interesting insight as to how to EV battery packs are created and why they’re so important to the ever-growing EV market. I’m confident that we will see more growth in the market in question, too!