Alkali metal-oxygen batteries promise high gravimetric energy densities but suffer from low rate capability, poor cycle life and safety hazards associated with metal anodes. A safe, high-rate and long-life oxygen battery that exploits a potassium biphenyl complex anode instead of the problematic potassium metal anode has recently been developed by Prof. Yi-Chun Lu, Associate Professor of the Department of Mechanical and Automation Engineering and her research team. This technology provides a safe and efficient solution for the storage of renewable energy sources such as solar and wind. The breakthrough was recently published in the world-leading scientific journal, Nature Materials, a sister journal of Nature.

Scientists have been searching for a battery that can pack in more energy, with a longer life and safer than the widely used lithium-ion battery. Offering a higher energy density and lower cost, the alkali metal-oxygen batteries (e.g. Li-O₂, Na-O₂, K-O₂) represent a promising energy storage solution for multi-scale applications including grid-scale energy storage, solar energy storage, and powering electric vehicles. However, metal-air battery systems have long been suffering from poor cycle life, unstable oxygen electrode and flammable metal electrode. These challenges have seriously impeded the development of rechargeable metal-air batteries. 

In the past four years, Professor Yi-Chun Lu and her team have been studying the origins of the instability of the oxygen batteries. Recently, they replaced the problematic potassium metal with an organic biphenyl anode (BpK) forming a potassium biphenyl complex-oxygen (BpK-O₂) battery, which achieves an unprecedented cycle life (3,000 cycles) with a superior average coulombic efficiency of over 99.84% at a high current density of 4.0 mA cm^-2. In addition, the reactions between the organic anode and bulk water or dimethyl sulfoxide (DMSO) proceed moderately without combustion, which makes the BpK-O₂ battery much safer compared with the oxygen batteries based on alkali metals. 

Global climate change continues to affect our environment and is exacerbated by greenhouse gasses produced by fossil fuels. Developing reliable renewable energy resources is critical for the sustainable development of our society. This organic-oxygen battery could be widely applied to large-scale electricity storage, small and medium-sized charging stations, and energy storage modules for the renewable energy harvesting systems such as solar panels and wind turbines. Professor Yi-Chun Lu said, “This technology has a strong potential application in distributed energy storage, which will greatly enhance the penetration of renewables into the power grid and help us in moving away from fossil fuels. In addition, the cost of the raw materials of the organic-oxygen battery is much lower than the materials used in alkali metal and ithium-ion batteries (e.g. cobalt), leading to a significant decrease in the cost of energy storage. We hope to further improve the cell voltage and energy density of the organic-oxygen battery and apply this design knowledge to other alkali-metal-oxygen batteries.”

More details:
www.mae.cuhk.edu.hk/~yichunlu
www.nature.com/articles/s41563-019-0286-7

The Faculty of Engineering and SenseTime Group Ltd (SenseTime) have recently launched a new collaboration on Artificial Intelligence (AI) education with the signing of a collaborative agreement. AI is the technology that uses machine intelligence to simulate human intelligence in performing tasks and solving problems. The application areas include visual perception, speech recognition, decision-making, machine translation, self-driving cars, and more. The technology has broad implications as a disruptive force that is reshaping the world and changing the ways humans live and work in the future.

CUHK, which has a pool of top-tier talents in AI and sophisticated scientific research facilities, will collaborate with the world’s leading AI company SenseTime to promote AI education in Hong Kong. The collaborative agreement covers joint efforts to bring up the new generation of AI talent in the coming three years. And through the participation in international AI competitions, exchange programmes and exhibitions, talents with outstanding performance are encouraged to enroll in the engineering programmes in universities. The two parties will also actively engage in future educational activities by encouraging the young generation to explore AI and improve their literacy level, which includes the positive and ethical use of AI, as well as the limitations and risks. In addition, both parties hope to extend their collaborative efforts to research activities on technological advancement and societal applications of AI. 

Professor Martin D. F. Wong, Dean of Engineering, CUHK, remarked, “AI is one of the key research areas of the Faculty, and developing young talent and promoting technology education is a strong belief we share with SenseTime. Building on our deeply established ties, I expect the collaborative efforts from this Agreement will lead to increased participation of young students in our educational activities which will ultimately cultivate a new generation of engineering leaders in AI.”

Mr. Hailong Shang, Managing Director of SenseTime Hong Kong, said, “At SenseTime, ‘Lead AI Innovation to Power the Future’ has always been our mission. While pushing ahead for technological innovations, we are also committed to promoting AI education for all. CUHK has long been renowned for its research and development work in AI. With this collaboration, we aim to join hands with CUHK to cultivate more exceptional AI talents and contribute to the AI communities in academia and industry alike.”