Critical breakthrough for enhancing battery capacity

5 Dec 2023
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Professor Ren Yang (right), Professor Liu Qi of the Department of Physics and their team have achieved pivotal breakthrough in battery technology.

A pivotal breakthrough in battery technology that has profound implications for our energy future has been achieved by a team co-led by CityU.

The new development overcomes the persistent challenge of voltage decay and can lead to significantly higher energy storage capacity.

Lithium-ion batteries (LiBs) are widely used in electronic devices, while lithium-(Li) and manganese-rich (LMR) layered oxides are a promising class of cathodes for LiBs due to their high capacity and low cost. However, the long-standing problem of voltage decay hinders their applications.

The team has addressed the issue by unlocking the potential of LMR cathode materials. In their research, they stabilised the unique honeycomb-like structure within the cathode material, resulting in longer-lasting and more efficient batteries.

By incorporating additional transition metal ions into the cathode material, the team reinforced the honeycomb structure, resulting in a negligible voltage decay of only 0.02 mV per cycle, the first time that LMR cathode material with such a low level of voltage decay has been reported.

The team develops novel battery technology with negligible voltage decay, resulting in longer-lasting and more efficient batteries which hold great potential for various applications.

Through advanced atomic-scale measurements and calculations, the team found that these interlayer transition metal ions act as a “cap” above or below the honeycomb structure, preventing cation migration and maintaining stability. The structure remained intact even at high cut-off voltages and throughout cycling, ensuring the batteries' structural integrity.

“Our work has solved the voltage decay problem in the LMR cathode, with a capacity almost two times higher than the widely used cathode materials, ultimately paving the way for more powerful and sustainable energy storage solutions,” said Professor Ren Yang, Head and Chair Professor of the Department of Physics.

These findings hold great potential for various applications, from powering electric vehicles to portable electronics. The next step involves scaling up the manufacturing process for large-scale battery production.

 

Professor Ren Yang, Head and Chair Professor of the Department of Physics (PHY), Professor Liu Qi, PHY.