Electric vehicles (EVs) are a primary method to reach a net zero transportation sector, but in addition to CO2Â emissions, overall sustainability is becoming an increased focus point. However, sustainability is a very complex topic that does not tend to deal with absolutes as many factors are involved. There are concerns about the sourcing of minerals such as lithium, nickel, cobalt, and others to manufacture battery cells, but the construction and materials used to make the battery pack should also be considered. With IDTechEx forecasting a 5.5-fold increase in EV battery demand from 2023 to 2034, the impact of materials on sustainable battery production and how batteries are dealt with at the end of their life becomes increasingly important.
Another key focus for the EV industry, which may seem unrelated at first, is the need to apply fire protection materials to prevent or delay thermal runaway propagating between cells and eventually outside of the battery pack. IDTechEx predicts this market to experience a 16.1% CAGR from 2023 to 2034. The obvious reason for this is to improve the fire safety of these vehicles in the rare cases where they ignite. The huge variety of battery designs that have been seen on the market leads to a similarly broad range of fire protection materials employed. These materials themselves can be more or less sustainable, but also, how they are employed can play a factor in how sustainable the EV battery industry will be.
Fire protection materials: Application and sustainability
Some options used for fire protection in EV batteries include ceramic sheets, encapsulating foams, mica sheets, aerogels, and many others. As an example, mica has come under scrutiny due to its mining processes, but this has been improving with the Responsible Mica Initiative (established in 2017), and many producers of final products take steps to source their mica as responsibly as possible. As materials suppliers move towards using more renewable energy in the production of their materials, this will also improve the overall sustainability of materials.
Aside from the materials themselves, how they are applied can play a role. For example, polyurethane foams are somewhat sustainable materials as polyurethane can be recycled, and its production is not very energy-intensive in comparison to some options. However, in EV battery packs, when applied as an encapsulating foam, it is typically done so in a way that is not meant to be dismantled. According to IDTechEx estimates, a 60kWh pack taking this approach uses approximately 8kg of foam. This means that if a pack has a fault, the whole pack may have to be replaced, or at the end of the pack’s life, dismantling becomes very difficult. As the market moves to more highly integrated battery designs like cell-to-pack architectures, there is generally an increased use of adhesives that are difficult to remove safely.
Recycling an EV battery is sometimes done by grinding the entire pack and removing the useful materials as best as possible. Recovery of key materials would be improved, and waste could be reduced by making packs easy to dismantle. However, the trade-off is in the battery performance, reliability, and cost. A pack without modules, bonded strongly together, reduces the number of components, improving energy density and reducing costs, at the expense of replacing very few packs under warranty rather than servicing them.
IDTechEx outlook
Sustainability is increasing in importance, but often not the first priority; it will often fall behind performance and cost. This balance is also difficult when considering fire protection materials, as these provide a crucial safety function that should not be compromised. Given there is a selection of materials that can provide sufficient fire protection, OEMs could start to have sustainability move up the list of priorities. Ultimately, it is difficult to say that one material category is better or worse in terms of sustainability, and OEMs will have to determine which materials will function best in their design but also discuss this with respective material suppliers to see how they source and manufacture their materials, as well as options for dismantling and/or recycling at end-of-life.
The IDTechEx report, “Fire Protection Materials for EV Batteries 2024-2034: Markets, Trends, and Forecasts”, predicts the market share and growth for various categories of materials, including ceramic sheets, mica sheets, encapsulating foams, aerogels, coatings (fire retardant and intumescent), phase change materials, and others. The report considers upcoming regulations and the shifts in battery design, such as cell format, cell-to-pack, and more, to determine volume and value forecasts across on-road vehicle categories, including cars, vans, trucks, buses, 2-wheelers, 3-wheelers, and microcars.
