On March 19, reporters learned from the Shanghai Academy of Spaceflight Technology (SAST)under China Aerospace Science and Technology Corporation (CASC) that a joint team from the 811th Research Institute of SAST and Nankai University has recently developed a hydrofluorocarbon electrolyte for high-energy-density, low-temperature lithium batteries. This marks a new breakthrough in China’s core lithium battery technology, which is expected to double the range of existing lithium batteries and significantly enhance their low-temperature resistance.

As a key component connecting the positive and negative electrodes of lithium batteries, the electrolyte conducts lithium ions, acting like an "expressway" between the two electrodes. It plays a critical role in the energy efficiency, operational stability and temperature adaptability of the battery.

Currently, commercial lithium batteries mainly use oxygen- and nitrogen-based ligands as electrolyte solvents. Although these solvents exhibit strong solubility for lithium salts, they restrict charge transfer, creating bottlenecks for further improvements in energy density and low-temperature performance. Data shows that conventional lithium batteries deliver an energy density of approximately 300 Wh/kg at room temperature, but this plummets to below 150 Wh/kg at -20°C.

To address this industry pain point, the joint team conducted years of research and overcame technical challenges such as the insolubility of lithium salts in fluorine-based systems. They synthesized a novel electrolyte solvent containing monofluorinated alkanes, which effectively reduces electrolyte viscosity, improves oxidation stability and low-temperature ionic conductivity, and enhances low-temperature energy output in high-energy-density lithium batteries.

According to researcher Li Yong from the 811th Institute of SAST, this breakthrough enables lithium batteries to achieve an energy density of over 700 Wh/kg at room temperature and approximately 400 Wh/kg at -50°C.

"For batteries of the same weight, energy storage capacity is improved by 2 to 3 times or more at room temperature. This can extend the cruising range of electric vehicles from 500–600 kilometers to 1,000 kilometers or even higher. Moreover, the battery can operate normally under the extreme low temperature of -70°C," Li Yong noted.

The breakthrough is expected to have broad application prospects.

In high-tech fields, it can provide endurance and load capacity for spacecraft, unmanned aerial vehicles (UAVs), intelligent robots and other equipment in extremely cold environments.

In daily life, it is poised to significantly increase the cruising range of electric vehicles and the standby time of mobile phones in low-temperature conditions, easing consumers’ anxiety over battery storage capacity and temperature adaptability.

Source: Science and Technology Daily