Chinese researchers develop lithium-sulphur battery for drones
Beijing (ANTARA) - Chinese researchers have developed a new approach to significantly improve the performance of lithium-sulphur batteries, a breakthrough that could one day enable drones to fly much further on a single charge.
The research, recently published in the journal Nature, paves the way for more durable and powerful batteries for low-altitude flight and other fields.
Most conventional drones currently rely on lithium-ion batteries, which are approaching the limits of their energy density capacity. This energy density, the amount of energy stored per unit of weight, is generally below 300 watt-hours per kilogram, leading to “range anxiety” that limits flight duration.
Lithium-sulphur batteries are considered a promising alternative due to their high theoretical energy density, as well as the abundance and low cost of sulphur.
However, in practice, these batteries face major challenges. During the charging and discharging process, sulphur undergoes complex chemical reactions that produce many soluble intermediate compounds. These intermediates tend to dissolve, slowing reactions and wasting energy.
A team led by Tsinghua Shenzhen International Graduate School (Tsinghua SIGS) proposed a new solution by introducing the concept of a “premediator” for sulphur electrochemistry.
“Think of it as a special additive compound that lies dormant in the battery until needed. When the sulphur reaction begins, the additive awakens right at the reaction site and starts working,” explained Zhou Guangmin, a researcher at Tsinghua SIGS.
Once activated, these molecules bind to the soluble intermediates and prevent them from dissolving. The molecules also help create fast pathways for electrical reactions, making the overall process much smoother and more efficient, said Zhou.
The team also redesigned the reaction network at the molecular level. The newly developed molecules can reduce the battery’s internal resistance by 75 per cent compared to conventional designs. In tests, the new battery operated stably for 800 charge-discharge cycles, retaining nearly 82 per cent of its capacity.
Even more impressively, the team created a practical pouch cell prototype with an energy density of 549 watt-hours per kilogram, almost twice that of most standard drone batteries currently in use.
“For drones, this is crucial. Higher energy density means longer flight times, greater payload capacity, and wider operational range. Delivery drones can fly further to transport packages. Power grid inspection drones can reach more towers in a single trip. Search and rescue drones can stay airborne longer when every minute counts,” said Zhou.
The team believes their molecular design strategy can also be applied to other fields, including flow batteries, lithium-metal batteries, and even direct battery recycling processes, according to Xinhua.