End of the lithium dilemma in the electric car market? China created water-based battery

It is still the result of research, but it has the potential to revolutionize the electric car industry: Chinese researchers have developed a water-based battery with almost twice the energy capacity of lithium cells.

Chinese researchers have developed a water-based battery, arguing that it is much safer and more energy efficient than “highly flammable” non-aqueous lithium batteries.

These aqueous batteries use water as a solvent for the electrolytes, increasing their safety. In turn, although traditional non-aqueous lithium-ion batteries have a high energy density, their safety is compromised due to the flammable organic electrolytes they use.

Interestingly, researchers claim that the new water-based batteries will have twice the energy density of traditional lithium-ion options, potentially revolutionizing the industry. Generally, these batteries have a lower energy density, due to the limited solubility of the electrolyte and the low voltage.

New water-based battery could revolutionize the electric car market

Chinese researchers' proposed high-energy density aqueous battery is based on the transfer of multiple halogen electrons.

In collaboration with the group of professor FU Qiang, from the Dalian Institute of Chemical Physics (DICP), LI Xianfeng, from the Chinese Academy of Sciences (CAS) and DICP, he developed a multielectron transfer cat based on bromine and iodine.

In a previously published study covering this new battery, researchers shared that the cathode achieved a specific capacity of over 840 Ah/L and an energy density of up to 1200 Wh/L on a catholyte basis in full battery testing. The researchers used a mixed halogen solution.

In order to improve the energy density of aqueous batteries, researchers used a mixed halogen solution of iodide ions (I-) and bromide ions (Br-) as electrolyte. As shared, they developed a multiple electron transfer reaction, transferring I- to the iodine element (I2) and then to iodate (IO3-).

The developed multi-electron transfer cathode had a specific capacity of 840 Ah/L. By combining the cathode with cadmium to form a complete battery, researchers achieved an energy density of up to 1200 Wh/L based on the developed catholyte.

Citing the researchers, Interesting Engineering explained that “Br- added to the electrolyte can generate polar iodine bromide (IBr) during the charging process, which facilitates the reaction with H2O to form IO3-.” Furthermore, he shared that “during discharge, IO3- can oxidize Br- to Br2 and participate in the electrochemical reaction to realize the reversible and rapid discharge of IO3-.”

Therefore, the bromide intermediate formed during the charging and discharging process optimized the reaction process, effectively improving the kinetics and reversibility of the electrochemical reaction.

Water battery has been tested successfully

As reported by the South China Morning Post, when researchers tested their electrolyte with a vanadium anode, they discovered that the battery life could be extended up to 1000 cycles, “demonstrating significant stability”.

Furthermore, the researchers argued that the energy density of their batteries “even exceeded that of some solid electrode materials” and that their cost could be comparable to that of traditional lithium batteries.

This study provides a new idea for the design of high energy density aqueous batteries and can expand the application of aqueous batteries in the field of electric batteries.

LI Xianfeng said, arguing that his work demonstrates that it is possible to develop aqueous batteries with high energy density and offers a development option for grid-scale energy storage and even electric vehicles.