China develops lithium-metal battery delivering energy density of 447Wh/kg at -40°F

Chinese researchers have developed a high-energy lithium-metal primary battery that combines long endurance with powerful bursts while operating at temperatures as low as -40°F (-40°C). Developed by a team led by researchers from the Dalian Institute of Chemical Physics under the Chinese Academy of Sciences (CAS), the 25Ah pouch-type battery is designed to maintain stable performance in extreme cold. According to Chinese online media reports, validation tests showed that the battery achieved an energy density exceeding 750Wh/kg at a low discharge rate. The technology could support applications requiring reliable, high-energy power in harsh and low-temperature environments. High-energy battery The new lithium-metal primary battery is designed to combine high energy density, long storage life and rapid power delivery, while continuing to operate reliably in temperatures as low as -40°F. The researchers developed a 25Ah pouch-type lithium-metal primary battery that achieved an energy density of more than 750Wh/kg under low-rate discharge conditions, according to Science and Technology Daily. Testing by the safety laboratory of the China Electronics Standardization Institute also found that the battery could increase its discharge rate by as much as 100 times, enabling short bursts of high-current output at up to 10C, reports the Global Times (GT). The C-rate indicates how quickly a battery can charge or discharge relative to its rated capacity. A 1C discharge means a battery can theoretically deliver its full rated capacity in one hour, while a 10C discharge allows the same capacity to be delivered in roughly one-tenth of an hour. This capability is particularly important for primary batteries, which are designed for single-use operation and are not intended to be routinely recharged. At room temperature, the new battery reportedly reaches a specific power of 4,487W/kg. It can sustain discharge at 4C and deliver short bursts at up to 10C, addressing a major limitation of conventional lithium primary batteries, which can offer high energy density and long shelf life but may struggle to release large amounts of energy rapidly. Cold-ready battery The battery also demonstrated significant performance at extreme cold. At -40°F, it retained an energy density of 447Wh/kg when discharged at 1C. Its annual self-discharge rate remained below 1 percent, indicating that the battery can retain most of its stored energy during extended periods of standby, reports GT. The combination of high specific energy, low self-discharge and high power output could be valuable in situations where batteries must remain ready for long periods but suddenly deliver substantial power. Potential applications include drones and robots operating in remote locations, spacecraft systems, field-deployed sensors, rescue equipment and other devices where regular battery replacement or recharging is difficult. Primary batteries are particularly useful in applications where charging infrastructure is unavailable or impractical. They can remain stored for long periods and provide power immediately when required, making them relevant to military operations, emergency response, rescue missions and forest-fire monitoring. According to the team, they achieved the performance improvement through a new cathode material based on a high-entropy oxide. The team has also established a pilot production line with an annual capacity of 10 tons, providing a pathway from laboratory-scale material development toward battery manufacturing. The battery has completed third-party testing and is undergoing additional validation for potential use in drones, robots, spaceflight simulators, and field sensor nodes. Further testing will determine how the technology performs under specific operating conditions and whether it can be scaled for broader commercial applications. Recommended ArticlesGet the latest in engineering, tech, space & science - delivered daily to your inbox.Jijo is an automotive and business journalist based in India. Armed with a BA in History (Honors) from St. Stephen's College, Delhi University, and a PG diploma in Journalism from the Indian Institute of Mass Communication, Delhi, he has worked for news agencies, national newspapers, and automotive magazines. In his spare time, he likes to go off-roading, engage in political discourse, travel, and teach languages.