The pursuit of safer, long-lasting, and cost-effective batteries for electric vehicles has achieved a significant milestone recently. According to tests conducted on a prototype solid-state battery developed by United States-based company QuantumScape, the battery retained an impressive 95 per cent of its capacity after completing 1000 charging cycles.

This corresponds to a total mileage of more than half a million kilometres for an electric car with a range of 500-600 kilometres.

Typically, in the development phase of a solid-state battery, the industry standard target is around 700 charging cycles and a maximum capacity loss of 20 per cent. The exceptional results from QuantumScape's prototype indicate a significant advancement in the realm of lithium-ion batteries.

The tests were carried out over several months by PowerCo, the battery company of global automaker Volkswagen, which announced this breakthrough. This solid-state battery presents a potential solution to various challenges currently faced by electric vehicle (EV) batteries, including cost, safety, capacity, charging time, and durability.

Unlike the lithium-ion batteries used in most EVs today, the battery tested by PowerCo employs a solid electrolyte instead of a liquid one.

The solid-state electrolyte offers improved temperature tolerance, leak resistance, and non-flammability compared to liquid electrolytes used in conventional lithium-ion batteries.

Studies have indicated that solid electrolytes can withstand higher temperatures, making them potentially suitable for conditions such as those prevalent in India.

While traditional EV batteries typically consist of two electrodes, a liquid electrolyte, and a separator, solid-state batteries replace the liquid electrolyte with a solid one, which also serves as a separator. This solid-state technology has been pursued for over four decades, aiming to harness the potential of solid-state and lithium-metal batteries, which offer significantly higher energy density and faster charging compared to traditional lithium-ion batteries.

QuantumScape's anode-free solid-state lithium-metal cell, constructed in 24 layers, holds promise for series cell production, with scalability being the next focus.

Anode-free cells, a notable innovation, draw lithium metal directly from the cathode during the initial charge, potentially leading to increased energy density.

Several automotive companies are heavily invested in solid-state battery technologies. Volkswagen Group, a major investor in QuantumScape since 2012, is among them. BMW has also invested in Solid Power to expand solid-state battery production, while Toyota and Hyundai have announced plans to launch solid-state battery EVs by 2025.