The future of EV batteries relies on multiple options

Next-generation EV battery technology will play a defining role in the automotive industry’s transition towards electrification. There are a lot of developments in solid state, sodium-ion, and metal air batteries. The question is whether any of these will be the breakthrough that propels the EV industry forward, or whether it will be a combination of all these combined. As with all technologies, these too come with their own set of challenges and advantages.

The current landscape: Lithium-ion and Solid-State   

Lithium-ion, the current top choice for EV batteries faces many limitations when it comes to battery range, price, charging speed, lifetime, and safety. While developers are working to remove these constraints, they are also exploring solid-state batteries which offer improved safety and increased energy density. Solid-state batteries replace the liquid with a solid polymer or ceramic electrolyte, offering superior thermal stability and enabling faster charging. In addition, solid-state batteries also provide a longer lifespan due to the reduced risk of dendrite formation.

Whereas this could translate to longer driving ranges and quicker charging, making solid-state a game-changer for widespread EV adoption is still far away. The manufacturing process is complex and expensive, and scaling up mass production will require continued advancements to bring down the cost.  

Sodium-ion: the economical option

Sodium-ion batteries present another intriguing option as sodium is significantly cheaper and more abundant than lithium. This provides an opportunity to lower battery production costs, making EVs more accessible for many consumers. The abundance of sodium also reduces reliance on lithium mining, which has environmental and ethical concerns. Sodium-ion also performs well in cold temperatures, making it a suitable option for regions with harsh winters. However, it has lower energy density and slower charging, as compared to lithium-ion, which may be a significant drawback for some consumers. Continued research is still needed to optimise performance.

Although in its early stages, sodium-ion batteries have the potential to play a crucial role, especially when it comes to making EVs more accessible and sustainable.

Metal-Air: the sustainable option

Metal-air is another emerging battery type, encompassing technologies like zinc-air, aluminum-air, and iron-air. These offer high energy density for extended driving ranges and certain metal-air batteries, such as zinc-air, utilise readily available elements—eliminating the need for complex and potentially harmful electrolytes for a more sustainable option. The use of abundant materials also promises the ability to reduce battery production costs. However, challenges like a shorter lifespan compared to lithium-ion and frequent recharging can significantly degrade the battery’s capacity. In addition, both lithium-air and some other metal-air batteries like aluminum, face the issue of metal dendrite formation. These structures can damage the battery and reduce its lifespan. Regardless, metal-air batteries still offer exciting possibilities for the future of EVs due to their high theoretical energy density and potential for a more sustainable approach.

The future landscape

The automotive and chemical industries are exploring new battery technologies with a range of chemistries and structures. This variety is crucial for the growth of the EV market, as a one size fits all approach doesn’t always work in every market. Just as internal combustion engines have various technologies like turbocharging, direct injection, and cylinder layouts, so will the future of EV batteries. Having multiple battery types enables automakers to customize vehicles to specific market demands.  While lithium-ion batteries will continue to be dominant for now, the industry is not reliant on it being the sole solution for an electrified future.

Matthew Borst is Automotive Brand Manager, at Keysight Technologies. Views expressed are of the author.