On 15 February, Sun Huajun, the CTO of BYD Lithium Battery, revealed key details about the company’s R&D progress and strategic agenda for solid-state batteries, with plans to begin commercial production for EVs from 2027.

At the China All-Solid-State Battery Innovation and Development Summit Forum, BYD announced that it would begin small-scale commercial production of EVs with all-solid-state batteries in 2027 and achieve large-scale output after 2030. The cells for these vehicles would be delivered from BYD’s 100GWh Bishan gigafactory, which is scheduled to begin operation in 2026 with an initial capacity of 20GWh.

Critically, BYD revealed that with large-scale mass production, it expects to achieve the same price for solid-state and liquid-state batteries. In other words, the final cost of solid-state batteries would be comparable to that of liquid high-nickel NCM batteries on a US$/kWh basis.

BYD’s current technical route for solid-state battery production combines high-nickel NCM (single-crystal) cathodes, silicon-based anodes, and composite halide sulphide electrolytes, which are distinctly different from SAIC’s polymer route and Toyota’s oxide route for solid electrolytes.

Safety remains a point of discussion for next-generation battery cells when considering existing solid-state battery products that have already been launched. Although the safety of these products has improved to a certain extent compared with liquid NCM batteries, there has been no such “revolutionary” change as previously envisioned by the sector. Trade-offs remain regarding charging rates and energy density - even for solid-state batteries, high energy density and high charging rates cannot be achieved simultaneously.

Therefore, solid-state batteries have the potential for step-wise advances in cell performance, although the pathway to achieving this will likely be more gradual to overcome present hurdles.