Solid-state batteries have been a hot topic among car makers in recent years, but what exactly are they and why should you care? Solid-state batteries utilize a solid electrolyte instead of the traditional liquid or gel-based ones. This electrolyte sits between the cathode and anode within the battery. The significance of this technology lies in its potential to revolutionize electric vehicles (EVs) by making batteries smaller, more energy-dense, and capable of supporting rapid charging without excessive heat generation. This advancement could lead to lighter, more cost-effective EVs with extended ranges.
To understand how this works, imagine a 10cm wide rectangle representing a battery. The anode and cathode are positioned at the ends, separated by a liquid or gel electrolyte and a salt membrane separator. The separator prevents the electrodes from touching, which can cause dendrite formation—a buildup of spiky structures that can short the battery or even cause fires.
Switching to a solid electrolyte, such as glass, ceramic, or solid polymer, brings several benefits. Firstly, it eliminates the instability of liquid electrolytes in a moving car. Solid electrolytes are more stable and less flammable, increasing safety. Secondly, the solid electrolyte can also function as the separator, reducing the size of the battery. This reduction in size inherently increases the energy density of the battery. Moreover, replacing the graphite anode with a lithium one could boost the energy density by up to 40%.
Another advantage of solid-state batteries is their improved thermal management. Current batteries slow down charging to prevent overheating, limiting the use of the battery’s full capacity and extending charging times. Solid-state batteries, however, can withstand higher temperatures, allowing for faster charging and more efficient use of the cells. Rapid charging also increases ionic conductivity, which helps prevent dendrite growth, with some studies suggesting it can even cause dendrites to self-heal.
Despite their potential, solid-state batteries are not yet available on the market. Challenges remain in making them durable and scaling up production. Retooling factories to accommodate the new technology is costly, and car makers are focused on reducing costs. It may be a few years before solid-state batteries are commonly used in vehicles, possibly appearing in niche or premium models by the end of the decade.
Interestingly, solid-state batteries are not a new concept. Michael Faraday, a pioneer in electrochemistry and electromagnetism, explored the technology long before our time. While the journey to mainstream adoption continues, the promise of solid-state batteries remains a pivotal moment in battery innovation.
Ilika plc (LON:IKA) is a pioneer in solid state battery technology enabling solutions for applications in Industrial IoT, MedTech, Electric Vehicles and Consumer Electronics.
