Solid-state batteries, valued for their high energy density and enhanced safety features, are deemed the ideal choice for the next generation of electric vehicles — and this technology has witnessed advancements recently.

Differing from conventional lithium-ion batteries, solid-state batteries employ a solid electrolyte, eliminating the risk of uncontrolled energy flow and fires while enabling greater energy density, resulting in more compact and lighter battery cells.

German auto giant Volkswagen said on Wednesday that its battery arm PowerCo has seen promising results with solid-state cells during recent tests. A prototype from its partner, QuantumScape, experienced only a 5 percent storage capacity loss after more than 1,000 charging cycles, equivalent to 500,000 kilometers on the road.

Volkswagen said it has "significantly exceeded" industry targets, set at 700 charging cycles and a maximum loss of 20 percent capacity.

"These are very encouraging results," PowerCo CEO Frank Blome said. "The final result of this development could be a battery cell that enables long ranges, can be charged super quickly and practically does not age," he added.

The United States solid-state battery specialist QuantumScape wants to expedite the market introduction of the cell "as quickly as possible", founder and CEO Jagdeep Singh said, but scaling up production of automotive-grade batteries has proved tricky.

The industrialization of solid-state batteries is confronted by high costs and the difficulty of balancing high electrical conductivity with good processing performance, says a report from China Auto Think Tank. In response, the semisolid-state battery pack emerges as a transitional solution, incorporating both solid-state and liquid-state electrolytes, with the liquid electrolyte comprising 5-10 percent of the composition.

Operating on solid-state battery principles, it boasts a cost comparable to traditional lithium-ion batteries and high compatibility with conventional lithium-ion battery production lines, significantly reducing equipment investment, the report notes.

Chinese battery providers have made advancements in recent years by developing semisolid-state batteries.

Beijing Welion New Energy Technology has provided semisolid-state battery cells with an energy density of 360 watt-hours per kilogram for the Nio ET7 sedan, featuring a 150 kilowatt-hours battery pack.

In mid-December, Nio announced the completion of the range challenge with the ET7, equipped with the 150 kWh semisolid-state battery, achieving a final driving mileage of 1,044 kilometers in 12.4 hours.

Welion said the mass supply semisolid-state batteries to Nio will start from April.

The company achieved a monthly installed capacity of 0.41 gigawatt-hours in November, marking the initial step into mass production of semisolid-state batteries.

Gotion High-tech has developed semisolid-state batteries with a single-cell energy density of 360 Wh/kg and has introduced prototype featuring a higher energy density of 400 Wh/kg.

Meanwhile, Ganfeng Lithium has provided semisolid-state batteries for the Dongfeng Aeolus E70 sedan and Voyah Passion sedan.

In late December, Chinese automaker Changan and Ganfeng Lithium announced a collaboration to develop solid-state batteries. The partnership involves establishing a joint venture with equal shareholdings, aimed at accelerating research, development and manufacturing of solid-state batteries.

The collaborative effort seeks to construct an internationally competitive base for solid-state battery technology, assisting its swift industrialization, Ganfeng Chairman Li Liangbin said.

The next generation of solid-state battery will be first installed in models of Changan's EV unit Deepal.

caoyingying@chinadaily.com.cn