Cobalt is what drives up the price of batteries. Japan just found a much cheaper alternative
Japan has developed a battery that does not contain cobalt or nickel, with an incredibly high energy density of 820 Wh/kg. The secret is in a new material based on lithium manganese oxide.
The problem with lithium batteries. Lithium batteries power virtually all of our electronics, and now our electric vehicles and energy storage systems.
However, for such large-scale use, they have two major drawbacks: low energy density, which results in larger and heavier battery packs, and the high cost and environmental impact of some of their components, starting with cobalt.
Ni/Co free battery. Nickel and cobalt are used to make the cathode, one of the electrodes responsible for the electrochemical reaction that charges and discharges batteries. Nickel increases capacity and energy density, while cobalt improves thermal stability, allowing the battery to retain its capacity longer.
Cobalt is the most expensive metal in a lithium battery, even more expensive than lithium itself. Its high cost is due to limited geographic availability: 70% is mined in the Democratic Republic of Congo, where political instability causes production to rise and fall.
Some of the mines are also regularly singled out for their inhumane conditions of detention and exploitation of children. Hence the interest in developing a battery that does not contain cobalt and its ever-present companion metal, nickel.
Japan found a way. A team of researchers from Yokohama National University has developed a promising alternative to the ubiquitous nickel-cobalt batteries. They started with LiMnO2 batteries, which use lithium and manganese oxides in their electrodes, but their performance is much lower.
After exhaustively studying LiMnO2 in its various forms using X-ray diffraction, scanning electron microscopy and electrochemical techniques, the researchers synthesized a nanostructured version with characteristics far superior to other forms of LiMnO2 and three times the energy density.
820 Wh/kg without voltage drop. Unlike other similar materials, the battery did not experience significant voltage drop during charge/discharge cycles. The new material retained 75% of its 820 Wh/kg capacity at very high charging rates.
The trick was to develop a mixed crystal structure known as a monoclinic lattice and to overcome other practical problems, such as manganese dissolution, by coating the material with lithium phosphate and using a highly concentrated electrolyte.
Much cheaper. Most importantly, the material can be synthesized using a simple and inexpensive method. This achievement could allow the production of high-performance batteries without relying on rare and expensive metals such as nickel and cobalt.
The researchers hope their work will help develop new technology that is competitive with existing options but is sustainable and environmentally friendly.
Images | Volvo, Pexel
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