Scientists at the University of Maryland and the US Army Military Research Laboratory have developed a new chemical type cathode without a transition metal for lithium-ion batteries. The opening allows you to increase the energy density of the storage devices, while maintaining their safety.
Using reversible conversion and intercalation of halogen in a graphite structure, the researchers presented an all-water lithium-ion battery with good cyclic stability and design energy density of 460 W / kg (total mass of cathode and anode). Unlike traditional lithium batteries, new cells use not only Li cations, but also halogen anions (LiCl and LiBr) for charge storage..
The power output of the created battery is comparable to that of existing devices, but the energy density is 25% higher. Moreover, such a battery is much safer. The new cathode is capable of holding 240 mA / g for an hour of operation due to the accumulation of lithium ions in four-volt cells. The team has demonstrated reversibility for 150 cycles.
In addition to portable batteries, this chemical composition can be used in devices that require high energies at the kilowatt or megawatt level. Applications are also justified when safety and toxicity are major concerns, including non-flammable storage devices for aircraft, ships or spaceships, and large storage systems..
Scientists talk about the approach of technology water-based batteries for commercial use. However, it is not yet known whether a durable prototype can be developed..
Recently the scientists also unveiled a prototype water battery that can be fully charged and discharged in just a few seconds.
text: Ilya Bauer, photo: ARL, auto-tuning