China’s solid-state battery race is splitting across different chemistries. Sunwoda’s automotive battery subsidiary, SEVB, is developing a polymer-composite electrolyte, while CATL remains focused on sulfide technology and has reiterated its aim of starting small-batch production in 2027. An update Sunwoda posted to the Shenzhen Stock Exchange’s investor platform on October 30 said its polymer cell had passed design and process verification and was still under customer evaluation. The customers and number of samples have not been disclosed; SEVB had said in May that customer testing was underway.
For its Xin Bixiao program, Sunwoda reports a 20 Ah cell with an energy density of 400 Wh/kg, more than 1,200 cycles and a 12-micron polymer-composite membrane. The cell uses a nanoscale, high-entropy silicon anode and passed a 200°C hot-box test. The company says its design can accommodate electrode movement and operate under external pressure below 1 MPa. These are cell-level figures, however, and do not establish how a finished vehicle battery would perform.
CATL confirmed its 2027 small-batch target to investors on October 27, following a 20 Ah solid-state prototype shown in 2024. SEVB is also pursuing sulfide: its roadmap includes a second-generation sulfide battery for 2027 and a cell exceeding 500 Wh/kg by 2030. Its connected pilot line has a designed annual capacity of 0.2 GWh. The article cites a sulfide electrolyte price of about €535 per kilogram, compared with €5.35 for conventional liquid electrolytes.
Sunwoda’s polymer route may ease pressure and manufacturing constraints associated with sulfide, but vehicle-level validation, cost, durability and scalable production remain unresolved. The company is also involved in a Guangdong aviation-battery research center targeting cells of at least 450 Wh/kg, with continuous discharge power density of 1,000 W/kg or more for eVTOL applications.