Lithium-ion battery modules (left) and alloys made of electrode materials (right)
[Click to enlarge image]

Honda Motor Co Ltd introduced its effort to reuse used lithium-ion (Li-ion) batteries as materials for nickel-metal-hydride (NiMH) batteries at Eco-Products 2015, which took place from Dec 10 to 12, 2015, at Tokyo Big Sight.

Specifically, Honda reuses the positive-electrode material of Li-ion battery as the negative-electrode material of NiMH battery. It also recycles electrolyte. The company aims to establish a technology that can promote the recycling of automotive Li-ion batteries, for which demand is expected to grow.

By disassembling cells into many components before the incineration of batteries, the battery recycling technology being developed by Honda saves labor and time of separating impurities after extracting nickel-cobalt alloy.

The electrode materials are separated into positive- and negative-electrode materials, and the positive-electrode material is melted to make nickel/cobalt/aluminum alloy. When the aluminum is removed, high-purity nickel-cobalt alloy can be obtained. This can be used as a negative-electrode material for NiMH batteries as it is. On the other hand, the negative electrode is melted to make copper alloy.

Because the new technology realizes a simple impurity separation process, it is expected to be used as a low-cost recycling technology, Honda said. This time, the company exhibited a nickel-cobalt alloy made by using the new separation technology.

Furthermore, with the latest method, separated electrolyte is also recycled instead of being incinerated, and cell cases are reused as they are.