Solid-State Batteries: The Next Big Thing in E-Mobility?

Up to twice as much energy at the same size: Solid-State Batteries (SSB) are at the forefront of current research and development in the field of electric mobility. They are considered the next big thing that could significantly improve the performance, safety, and range of electric vehicles (EVs). Compared to the currently dominant lithium-ion batteries, which use a liquid or gel-like electrolyte, they offer several crucial advantages.

2024/03/18 - Solid-state batteries replace the liquid electrolyte with a solid one. This not only allows for higher energy density but also increases safety, as the risk of leaks and the resulting fires are minimized.

There are three types of solid electrolyte system, namely oxides, sulfides, and polymer electrolyte. While oxides and sulfides have a transport mechanism which allows only lithium ions to move (therefore reducing polarization), polymer electrolytes allow both cation and anion to be charge carrier. The solid nature of the electrolyte leads to higher thermal stability. This reduces the need for complex cooling systems required in traditional lithium-ion batteries to prevent overheating during charging. Without the limitations caused by heat development, solid-state batteries can be charged faster without the risk of damage from excessive temperatures. Furthermore, in theory, they may offer a barrier to lithium dendrite formation[1], which may allow the use of high energy dense lithium anode in future application, thereby increasing the energy density of the battery.

Despite their obvious advantages, the technology is still in the research and development phase. The challenges in the industrial production of solid-state batteries lie mainly in the choice of materials for the solid electrolyte and the scaling of production processes. Materials such as lithium phosphate and various types of sulfides, oxides, and polymers are being examined to ensure high ionic conductivity and stability.

SVOLT Energy Technology is also advancing the development of solid-state batteries. As a spin-off from Great Wall Motors and with extensive expertise in battery research and production, the company is working on innovative solid-state electrolyte materials and structures to optimize ionic conductivity and improve the interaction between the electrodes and the solid electrolyte. SVOLT places particular emphasis on making batteries not only more powerful and safer but also more cost-efficient to make e-mobility accessible to a broader market.

Future Prospects

In the coming years, research and development in solid-state batteries is expected to make significant progress. By the end of this decade, the first commercially usable solid-state batteries could be deployed in electric vehicles. This development would enable a significant increase in the range of EVs, shorten charging times, and further advance the general acceptance of e-mobility.

SVOLT is working with investments in research and development as well as partnerships in the automotive industry to demonstrate the commercial feasibility of solid-state batteries and build the necessary production capacities. Vaneet Kumar, Vice President European Customer Business Unit & Research & Development SVOLT Europe: ‘Current lithium-ion batteries have energy densities up to around 300Wh/kg. The introduction of solid-state electrolyte combined with lithium metal anode could bring the energy density up to 450Wh/kg with conventional Nickel-rich cathode materials. SVOLT is working to commercialize solid state batteries with energy density in excess of 350Wh/kg and up to 500Wh/kg by the end of the decade’.

Conclusion

Solid-state batteries represent a promising future for e-mobility, with the potential to significantly improve the performance, safety, and economy of electric vehicles. While technical and economic challenges are yet to be overcome, companies like SVOLT are advancing research and development to bring this advanced battery technology to market readiness. The next few years will determine whether and how solid-state batteries could reshape the landscape of e-mobility.

[1] Dendrites are needle-shaped lithium deposits that can form on the surface of the anode (negative electrode) during the charging process. Their formation poses a significant safety risk, as they can penetrate the separator layer between the anode and the cathode (positive electrode). This creates the risk of an internal short circuit, leading to overheating, fire, or even the explosion of the battery. Dendrite formation also diminishes the performance of the battery, leading to capacity loss and a reduced lifespan by disrupting the efficiency of ion transport between the electrodes.