Lithium-sulfur and carbon nanowires battery

Source: Nano Letters & Technology Review

Right now your cell phone, laptop, and most EV vehicles being engineered use rechargeable lithium ion batteries. However, the specific energy of existing lithium ion batteries is still insufficient for many applications due to the limited specific charge capacity of the electrode materials. Two years ago we heard of a potential battery breakthrough by Stanford University professor Yi Chui using carbon nanowires. The recent development of sulfur/mesoporous carbon nanocomposite cathodes represents a particularly exciting advance. In full battery cells, sulfur-based cathodes have to be paired with metallic lithium anodes as the lithium source, which can result in serious safety issues. The researchers at Stanford report a novel lithium metal-free battery consisting of a Li₂S/mesoporous carbon composite cathode and a silicon nanowire anode. This new battery yields a theoretical specific energy of 1550 Wh kg⁻¹, which is four times that of the theoretical specific energy of existing lithium-ion batteries based on LiCoO₂ cathodes and graphite anodes (410 Wh kg⁻¹).  Besides increasing the lifespan and storage capacity, the new design should also be safer and result in less fires, since the materials won’t expand and pierce the separator materials which occasionally happen now. The next hurdle before this design can be used, is figuring out a way to stop the production of poly-sulfides during each charge and discharge so the battery lasts more than 40-50 charge cycles.