Croucher scholar reveals innovative battery design

31 October 2023

A research team led by Professor Dennis Y.C. Leung of the University of Hong Kong has designed a high-performance quasi-solid-state magnesium-ion (Mg-ion) battery. 

The design offers a sustainable, safe, and high-energy-density alternative to conventional lithium-ion batteries addressing limitations of material scarcity and safety concerns. Details of the invention were published in Science Advances.

In recent years Mg-ion batteries have emerged as a promising technology especially in the light of the limitations of lithium-ion. There are problems however including a narrow electrochemical window in aqueous or water-based systems and poor ionic conductivity in non-aqueous systems.

Addressing these obstacles Leung and his team team first developed a water-in-salt Mg-ion battery with an operating voltage above 2V. This work lead to the design of a quasi-solid-state magnesium-ion battery which uses a polymer-enhanced electrolyte to control the interaction between protons and metal ions. 

The battery has a voltage plateau at 2.4V and an energy density of 264 W·h kg⁻¹ better than existing Mg-ion batteries and close to the performance of Lithium ion.

“Our quasi-solid-state magnesium-ion battery combines the best of both worlds, offering the high voltage of non-aqueous systems and the safety and cost-effectiveness of aqueous systems," said Leung.

Leung and his colleagues conducted extensive cycling tests. At extreme subzero temperatures of -22°C the battery retained 90% of its capacity after 900 cycles. The battery is non-flammable and resistant to over 40 times atmospheric pressure. 

“The advanced electrolyte development strategy presented in our research holds potential beyond magnesium-ion batteries, extending to other multivalent metal ion batteries, such as zinc-ion and aluminium-ion batteries," said Leung.

Professor Dennis Y.C. Leung was awarded a fellowships by the Croucher Foundation in 1987. To view his Croucher profile click here.