The future of electric vehicles (EVs) is being revolutionised by smaller, more efficient battery packs. Not only do they make EVs more affordable and environmentally friendly, but they also enhance safety and performance. Ilika’s latest advancements in solid-state battery (SSB) technology are setting new benchmarks, ensuring the next generation of EVs is lighter, safer, and more efficient.
Ilika recently conducted safety tests on its Goliath solid-state cells, revealing their impressive resilience under stress. In a nail penetration test, these cells neither exploded nor ignited, maintaining external temperatures below 80°C. In contrast, commercially available lithium-ion batteries exhibited severe swelling, rupturing, and fire in what is known as thermal runaway. These results reinforce the potential of SSBs in delivering safer energy solutions.
Despite concerns, EVs are statistically far less prone to fires than internal combustion engine (ICE) vehicles. Data from EV FireSafe indicates that from 2010 to 2024, there were only 511 reported thermal runaway incidents in battery and plug-in hybrid EVs—just 1.3 incidents per 100,000 vehicles. In comparison, ICE vehicles experience 1,530 fires per 100,000 vehicles. This discrepancy highlights the extensive safety measures integrated into EV battery designs, including impact protection, temperature regulation, and fire containment systems. However, these safety features come at a cost—weight. EVs are typically 20% heavier than ICE vehicles, with battery packs comprising up to 30% of the vehicle’s weight.
The composition of a battery pack extends beyond just the cells. Cells, whether cylindrical, prismatic, or pouch-type, are grouped into modules, then assembled into packs with cooling systems, protective casings, sensors, and structural supports. The efficiency of this assembly is measured by the Cell-to-Pack Ratio (CTPR). A higher CTPR indicates a more optimised battery pack with reduced non-cell weight. Typically, lithium iron phosphate (LFP) battery packs exhibit a higher CTPR than nickel manganese cobalt (NMC) packs, as LFP cells are inherently safer and require less structural reinforcement.
To enhance battery performance and reduce weight, several strategies are being pursued. Increasing nickel content in NMC cells improves energy density, while modifications to LFP, such as adding manganese to create LFMP, also boost performance. Structural innovations, like BYD’s Blade battery, minimise the need for modules, directly integrating cells into the pack. Additionally, lightweight materials, such as aluminium trays from Constellium and thermally active adhesives from Henkel, are reducing battery pack weight. However, these innovations are reaching their limits.
Enter solid-state batteries. By replacing liquid electrolytes with solid or gel-like materials, SSBs significantly enhance safety, eliminating the risks of separator melting and electrolyte decomposition seen in conventional lithium-ion batteries. SSBs not only offer energy densities comparable to high-performance NMC cells but also provide safety levels akin to LFP cells. This breakthrough means EV manufacturers can produce lighter vehicles with the same energy capacity or vehicles with extended range while maintaining the same weight.
Temperature tolerance is another key advantage of SSBs. Conventional lithium-ion batteries operate efficiently between 15°C and 45°C, requiring sophisticated thermal management systems to maintain optimal conditions. Overheating, particularly during fast charging, degrades battery performance and lifespan. With their higher temperature tolerance, SSBs could reduce reliance on complex cooling systems, making fast charging more viable and efficient.
While SSBs present game-changing benefits, a few challenges remain. Both lithium-ion and solid-state cells perform best when under compression, meaning additional structural support may be required. Additionally, all battery chemistries struggle with cold temperatures, potentially necessitating heating systems for vehicles operating in extreme climates.
For EV drivers, battery advancements translate into real-world benefits. Faster charging means less time spent waiting and more time on the road. Enhanced energy density leads to extended range, whether for a cross-country trip or daily commutes. Improved durability ensures that EVs remain reliable for years, even achieving distances equivalent to a journey to the moon and back.
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.
