Combined efforts from the scientists at the University of Maryland and the US Army Research Laboratory have resulted in a groundbreaking new technology – the "Water-in-Salt" aqueous Lithium ion batteries!
A team of scientists - led by Chunsheng Wang, an associate professor in UMD's Department of Chemical & Biomolecular Engineering, and Kang Xu, senior research chemist at the Sensor and Electron Devices Directorate of ARL - made an important breakthrough in the aqueous (water-based) batteries by doubling their voltage.
The lithium-ion batteries that are widely used today can operate at higher voltages and discharge at a slower rate, however they also pose a dangerous risk. They can overheat quickly (fire risk), they contain poisonous chemicals and are extremely hazardous to the environment. A much safer and equally greener solution is to use the water-based electrolytes, but these were, until now, commercially of no interest.
The scientists now used the kind of type of water-based electrolytes that contain exceptionally high concentrations of "a carefully selected Lithium salt". By doing so they managed to trigger a chemical transformation, which resulted in the "formation of a thin protective and stabilizing film on the anode electrode for the very first time in a water-based battery, " which is scientifically called the SEI or a Solid Electrolyte Interphase. With SEI, the desired commercial performance of the batteries can be achieved, but so far this was not possible in non-aqueous electrolytes.
According to the journal Science, Wang stated: "Through this work we were able to increase the electrochemical window of aqueous electrolyte from less than 1.5 Volts to ~ 3.0 Volts and demonstrated high voltage aqueous full Lithium-ion cell with 2.3 Volts, showing for the first time that aqueous batteries could seriously compete in terms of power and energy density with the non-aqueous lithium-ion batteries that power our mobile, digital lifestyle."
Photo credit: University of Maryland
Further research is to follow, however the new technology already predicts reduced manufacturing costs of the new batteries, an improved battery recyclability, greater safety and non-toxicity; possible use includes airplanes, spaceships, submarines, while these non-flammable batteries are aslo ideal for powering the electric vehicles, naval vessels or spaceships, and in medical devices like pacemakers.
And all that with the same or greater power, efficiency and longevity that we are used to see in current Lithium-ion batteries.