As the number of mobile electronic devices from smart phones to e-bikes increases steadily worldwide, so does the demand for small, lightweight, and powerful batteries. Experts are looking at lithium-sulfur batteries as the next step in energy storage.

A team of chemists — including Ludwig Maximilian University of Munich Professor Thomas Bein and Linda Nazar of the University of Waterloo, Canada — have developed porous carbon nanoparticles, in which the sulfur is incorporated, so that a maximum capacity of the battery is reached. "We have a high initial capacity of 1200 mAh/g and were able to obtain good cycling stability," said Bein.

The carbon structure also reduces the so-called polysulfide problem. Polysulfides are formed as intermediate product of electrolysis and can affect the charging and discharging of the battery. The scientists can draw on the carbon material they developed with a thin silicon oxide layer, which protects against polysulfide without impairing the conductivity.

With their new material, the researchers presented a new record - the mesoporous carbon nano-material has the largest internal pore volume (2.32 cm3/g) and an extremely large surface area of 2445 m2/g.

(Ludwig Maximilian University of Munich)