Lithium sulphur batteries offer a theoretical energy density more than five times that of lithium ion batteries. Researchers used a graphene sponge-like aerogel to enable this.
“Researchers at Chalmers University of Technology, Sweden, recently unveiled a promising breakthrough for this type of battery, using a catholyte with the help of a graphene sponge.
The researchers’ novel idea is a porous, sponge-like aerogel made of reduced graphene oxide that acts as a free-standing electrode in the battery cell and allows for better and higher utilisation of sulphur.
A traditional battery consists of four parts. First, there are two supporting electrodes coated with an active substance, which are known as an anode and a cathode. In between them is an electrolyte, generally a liquid, allowing ions to be transferred back and forth. The fourth component is a separator, which acts as a physical barrier, preventing contact between the two electrodes whilst still allowing the transfer of ions.
The researchers previously experimented with combining the cathode and electrolyte into one liquid, a so-called ‘catholyte.’ The concept can help save weight in the battery, as well as offer faster charging and better power capabilities. Now, with the development of the graphene aerogel, the concept has proved viable, offering some very promising results….
Most commercially available batteries are lithium-ion batteries. But this type of battery is nearing its limits, and new chemical approaches are becoming essential for applications with higher power requirements. Lithium sulphur batteries offer several advantages, including much higher energy density.
The best lithium ion batteries currently on the market operate at about 300 watt-hours per kg, with a theoretical maximum of around 350. Lithium sulphur batteries meanwhile, have a theoretical energy density of around 1000-1500 watt-hours per kg.”…
“The researchers note, however, that there is still a long journey to go before the technology can achieve full market potential. “Since these batteries are produced in an alternative way from most normal batteries, new manufacturing processes will need to be developed to make them commercially viable,” says Aleksandar Matic.
Read full article Graphene sponge helps lithium sulphur batteries reach new potential
Source: Phys Org, Chalmers University of Technology
Image: An illustration of the Chalmers design for a lithium sulfur battery. The highly porous quality of the graphene aerogel allows for high enough soaking of sulfur to make the catholyte concept worthwhile. Credit: Yen Strandqvist/Chalmers University of Technology