CHAPTER 11 Mechanical Packaging and Material Selection In this chapter, we will discuss how to do a “back of the napkin” estimate of a battery pack’s physical size and volume. We will also look at various types of packaging materials and solutions, ingress sealing protection considerations, shock and vibration considerations. Perhaps the first and most important statement we can make about battery packaging is this: there is no standard size lithium-ion battery pack and there is not likely to be one in the near future. This is a question that is quite frequently asked but the reason that there is not likely to be any standardization around battery packs is relatively simple:
each battery pack is designed to fit one or two different vehicle architectures for a single manufacturer. Every vehicle manufacturer has different architectures, different ways that the vehicles go together, different places they mount, and install different component. In larger stationary systems, there is a direction to use standard 19-inch-server racks to install lithium-ion batteries into. However, some battery manufacturers have developed different energy storage system (ESS) mounting solutions. Because of these issues standardization at the module or pack level is not all that likely at least not in the near term.
A secondary reason that standardization is a challenge is that almost every electrified vehicle on the market today is a “retrofit.” In other words, it is a vehicle that was designed for a gasoline or diesel internal combustion engines where the manufacturers are trying to find existing space in which to package a battery system, rather than a vehicle that was designed from the ground up, to be an electrically powered vehicle. This means that the batteries are being mounted in places that in a ground up design they likely would not be mounted—in the trunk, under seats, in the transmission tunnel, in the fuel tank location.
While this is the state of the automotive industry today, there will come a time when we move to more purpose built applications. Vehicles tend to go 10 to 15 years between “all-new” architecture redesigns. This means that we are probably two to three battery product genera- tions ahead of a time when vehicle architectures are designed with electrification in mind. This means designing the battery in, instead of trying to package it in an existing space. Today, there are only a few manufacturers, such as Tesla, who offer electrified vehicles that are ground up designs, but more will move this way over time.
As we begin to look at the mechanical aspects of lithium-ion ESS, it is usually best to begin with the requirements. What is the application? Where will it be mounted or installed? If an The Handbook of Lithium-Ion Battery Pack Design. http://dx.doi.org/10.1016/B978-0-12-801456-1.00011-7 Copyright © 2015 Elsevier Inc. All rights reserved. 131