A team of Chinese researchers has made a significant breakthrough in battery technology by developing a high-energy-density aqueous battery based on halogen multielectron transfer, according to the Chinese Academy of Sciences (CAS).
Traditional non-aqueous lithium-ion batteries, while offering high energy density, pose safety risks due to their use of flammable organic electrolytes. In contrast, aqueous batteries use water as the electrolyte solvent, enhancing safety but typically at the expense of energy density.
In a study published in the journal Nature Energy, the research team led by Li Xianfeng from the Dalian Institute of Chemical Physics (DICP) of the CAS, in collaboration with Fu Qiang’s team from the same institute, developed a multielectron transfer cathode utilizing bromine and iodine. This innovation achieved a specific capacity exceeding 840 ampere-hours per liter.
To enhance the energy density of aqueous batteries, the researchers employed a mixed halogen solution containing iodide and bromide ions as the electrolyte. They established a multielectron transfer reaction progressing from iodide ions to elemental iodine and then to iodate.
By combining this advanced cathode with metallic cadmium to form a complete battery, the team achieved an impressive energy density of up to 1,200 watt-hours per liter based on the catholyte.
During the charging and discharging process, the formation of a bromide intermediate optimized the reaction, effectively improving the kinetics and reversibility of the electrochemical reaction.
“This study provides a new direction for the design of high-energy-density aqueous batteries and may expand aqueous battery applications in the power battery field,” said Li.
Reference(s):
Chinese researchers develop high-energy-density aqueous battery
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