TOKYO – High-capacity and reliable rechargeable batteries are essential for various devices and modes of transportation and play a crucial role in transitioning to a greener world. However, the production of batteries involves the use of elements such as cobalt, which contributes to environmental, economic, and social issues. Researchers from the University of Tokyo, as part of a team, have now presented a viable alternative to cobalt that shows promising results in battery chemistry.
Lithium-ion batteries (LIBs) are commonly used to power electronic devices like laptops and smartphones. They are also gaining popularity for electric cars and home batteries in conjunction with solar panels. While LIBs have numerous benefits, they also have drawbacks. One challenge is the need for higher energy density to make batteries last longer and power more demanding devices. Additionally, batteries degrade over time, and it would be advantageous if they could survive more recharge cycles and maintain their capacity.
Cobalt, a rare element, is widely used in the electrodes of LIBs. The main source of cobalt is located in the Democratic Republic of Congo, and it poses environmental and labor concerns. Transitioning away from cobalt is crucial for improving lithium-ion batteries. A team of researchers led by Professor Atsuo Yamada has developed a new combination of elements for the electrodes, including lithium, nickel, manganese, silicon, and oxygen. These elements are more abundant and less problematic to produce and work with.
The new electrodes and electrolyte created by the research team not only eliminate the use of cobalt but also improve upon current battery chemistry. The energy density of the new LIBs is about 60% higher, potentially resulting in longer battery life. Moreover, these batteries can deliver 4.4 volts compared to the usual 3.2-3.7 volts of typical LIBs. The recharge characteristics have also seen significant improvement, with test batteries being able to fully charge and discharge over 1,000 cycles while only losing about 20% of their storage capacity.
The research team acknowledges that there are still minor reactions to mitigate to improve the safety and longevity of the batteries even further. However, the results so far are promising and point towards the development of improved batteries for various applications. The underlying concepts of this research can also be applied to other electrochemical processes and devices, including different types of batteries and applications like water splitting, ore smelting, and electro-coating.
Source: University of Tokyo, Department of Chemical System Engineering.
