Chinese researchers make breakthrough in field of solid-state batteries with soybean protein

In China, on November 2, 2025, a Tsinghua University research team achieved a breakthrough in the field of solid-state batteries by successfully developing an innovative solid-state electrolyte based on soybean protein, which is expected to provide an efficient, long-life green solution for next-generation batteries.

As a renewable resource, soybean protein is characterized by low cost, non-toxicity, and biodegradability. The research team enhanced its ionic conductivity through chemical modification, and the formed three-dimensional network structure possesses both high strength and flexibility, perfectly meeting the mechanical requirements of solid-state electrolytes.
Experimental results showed that solid-state batteries assembled using this electrolyte performed excellently: they operated stably for 2,000 hours at 60°C; even at a high temperature of 120°C, they maintained 75% of their initial capacity after 800 charge-discharge cycles. This characteristic gives them a unique advantage in high-temperature application scenarios, whereas traditional lithium-ion batteries face performance degradation and safety risks when temperatures exceed 60°C.
The soybean protein electrolyte forms a thin and uniform stable interface layer with the electrode, and its good flexibility effectively accommodates volume changes during battery charge and discharge cycles, fundamentally solving the industry challenge of battery performance degradation caused by interface instability.
Life cycle assessment data confirmed that the material’s environmental impact throughout the entire preparation process is significantly lower than that of other organic electrolytes, while also releasing fewer toxic and volatile compounds during application.