Scientists from the University of Twente in the Netherlands have created an experimental lithium-ion battery that features a new type of electrode with an open and regular crystal structure, which can effectively significantly increase the charging speed of lithium-ion batteries to 10 times that of today.
Lithium-ion batteries have two electrodes, namely the cathode and the anode. Currently, these anodes are made of graphite, which works well in many ways, but it cannot adapt to ultra-fast charging speeds without breaking down.
To this end, scientists look for new or improved anodes, one of which is materials with a nanoscale porous structure. Anodes of this nature are expected to have a larger contact area with the liquid electrolyte that transports lithium ions, and at the same time make it easier for ions to diffuse into the solid electrode material, ultimately allowing the device to charge faster. But the disorder and randomness of the channels in the porous nanostructures can cause these structures to collapse during charging, while also reducing the density and capacity of the battery and causing lithium to accumulate on the surface of the anode, thereby reducing its performance with each cycle. In addition, the manufacture of these materials is very complex, involving harsh chemicals and generating a lot of chemical waste.
Scientists from the University of Twente in the Netherlands have found a suitable alternative – nickel niobate. Nickel niobate has an open and regular crystal structure that has identical, repeating ion transport channels.
The researchers integrated this nickel niobate anode into a complete battery cell and tested its performance, and found that it provided ultra-fast charging rates nearly nine times faster than lithium-ion batteries. In addition, nickel niobate is more compact than graphite, so it has a higher volumetric energy density, which may make commercial versions of the battery lighter and more compact. The scientists also reported that the anode material has a high specific capacity of about 244mAh/g, and because nickel niobate changes little in volume during operation, it still has an 81% capacity retention rate after 20,000 cycles. The manufacturing process of nickel niobate is also much simpler than other nanostructured materials and does not require a clean room for assembly.
These results demonstrate the energy storage potential of nickel niobate anodes in practical battery devices. There is direct potential in grid applications, powering electric machinery that requires fast charging, or in heavy electric vehicle transportation. However, further research and problem solving are needed to see them suitable for standard electric vehicles.