Sumitomo Metal Mining Co., Ltd. has verified that nickel and cobalt from secondary batteries such as used lithium ion batteries (LIB) can be reused as a raw material for cathode material of LIBs through recovery and purification. Additionally, through its original lithium recovery technology, the company have established a new recycling process that is able to recycle copper, nickel, cobalt and lithium from used secondary batteries. Aiming for the creation of a sustainable circular economy, SMM has been engaging in the practical implementation of horizontal recycling* of metal as battery materials. These recycled metals include used secondary batteries and scrap from manufacturing processes. In 2017, the existing smelting and refining processes at the Toyo Smelter & Refinery (Saijo City, Ehime Prefecture) and the Niihama Nickel Refinery (Niihama City, Ehime Prefecture) were utilized in the practical implementation of copper and nickel recycling and the company were able to realize Japan's first “battery to battery” recycling with used secondary batteries. Moreover, in 2019, through a combination of pyrometallurgical smelting and hydrometallurgical refining processes independent of its existing processes, the company developed a new recycling process for the difficult-to-recover cobalt and have continued to test it at the pilot plant the company constructed in Niihama City, Ehime Prefecture. Now, the company have optimized processes at this pilot plant, and have been successful in the recovery of a high-purity nickel-cobalt mixture by stably and efficiently separating out the impurities in used secondary batteries. Moreover, the company manufactured and evaluated LIB cathode material that the company made from the nickel-cobalt mixture. The company were able to verify that the performance of those batteries was equivalent to that of batteries manufactured using existing raw materials derived from natural resources.