Scientists build ion-selective membrane for ultra-stable lithium sulfur batteries
Posted onDecember 30, 2013
Advanced energy storage systems are highly desired to fill the gap between currently available battery systems and high performance electronic devices or even electric vehicles. As the commonly-used lithium ion battery systems are approaching their theoretical energy density value, lithium-sulfur batteries are considered to be one promising candidate, exhibiting much higher theoretical energy density at 2600 Wh/kg (around 3-5 times that of the lithium ion batteries). However, the practical applications of lithium-sulfur batteries are hindered by the complexity of this electrochemical system, especially the insulate nature of sulfur and the so called “shuttle effect”, which means the diffusion and reaction of the cathode intermediate polysulfide with the anode side.
Researchers from Tsinghua University in Beijing, led by professors Qiang Zhang and Fei Wei, have developed a new strategy to build ultra-stable lithium-sulfur batteries based on an ion selective membrane system. With this new membrane system, the cyclic degradation of the cell was significantly reduced to 0.08 % per cycle within the first 500 cycles. Meanwhile, the coulombic efficiency of the battery can also be improved by around 10 %, which may greatly benefit the energy efficiency of the battery system. The team has published their findings in a recent issue of Energy & Environment Science.