According to Chinese media, battery maker Svolt Energy has started the first trial production of semi-solid-state batteries that will supply BMW Mini’s next-generation models. These are expected to be delivered ‘en masse’ to begin around 2027. BMW added Svolt in mid‑2023, as its third major Chinese battery supplier, alongside CATL and Eve Energy.
These newly developed semi-solid batteries are expected to offer an initial estimated energy density of 300 Wh/kg, while the battery maker aims for 360 Wh/kg with its second-generation semi-solid cells and 400 Wh/kg in future all-solid-state versions.
To compare, today’s cheaper LFP batteries (Lithium Iron Phosphate) have an average density of 150–180 Wh/kg. In contrast, more expensive NMC batteries (Nickel Manganese Cobalt) offer 220 to 280 Wh/kg, more commonly found in premium EVs with greater range.
Higher density means more range
Why does that matter? The higher Wh/kg, the longer the range of the EV will be without increasing battery size and weight. Svolt’s first-generation semi-solid batteries, with a capacity of 140 Ah, are soft-pack batteries featuring an energy density of 300 Wh/kg and a very low cost, according to a report by China Star Market.
Svolt today is one of China’s largest battery manufacturers, with a battery installation volume of 1.20 GWh, ranking ninth among Chinese battery makers. It has at least 11 production sites in China and one in Thailand, plus previously planned plants in Germany, which were later cancelled.
Spin-off from Great Wall Motors
It was founded in 2018 as a spin-off from Great Wall Motor’s in-house battery division, headquartered in Changzhou, Jiangsu Province, China. Great Wall Motors remains Svolt’s largest customer, supplying the Ora, Haval, and Wey EVs and hybrid models with batteries. Other known customers include Stellantis, which signed a long-term battery supply deal in 2021, as well as Leapmotor, Donfeng, Xpeng, and Geely/Zeekr.
Svolt leads in cobalt-free nickel-manganese (NMX) cell innovation, and also targets mass-market all-solid-state solutions in the years ahead. It’s already producing high-performance “Short Blade” LFP and NMC cells that charge from 10% to 80% in under 10 minutes.
SVolt is said to have set up two dedicated cell lines and battery pack assembly lines tailored for BMW’s new-generation Neue Klasse EV platform, starting in 2025, offering energy densities of around 240–270 Wh/kg, typical of its cobalt-free NMX chemistry.
