Lithium ion battery industry has been growing on the fast track since its first commercial production in early 90’s. The applications of lithium ion batteries are in a very large range now days, from wearable devices to mega energy storage, and, it is replacing other chemistries even in some very conservative applications.
Growing along with other type of cathode materials, nickel-based cathode materials are becoming more important for applications such as EVs etc. It is not only because of the lower cost than Lithium Cobaltate, but also the higher energy density. Even more importantly, the availability of nickel metal is 20x more than Cobalt. The overall implication is the higher nickel in cathode materials, the lower cost, the securer supply, the better performance.
Nowdays, most Nickel-based cathode materials are the results of sintering mixed metal hydroxide (i.e. precursor) with lithium salts or hydroxide. However, most, if not all, precursor production process is the traditional process as showed in below diagram 1. The process can make good precursors but it also generates over 15 metric tons of effluent (contents Ni2SO4, Ammonia, fine solid particles etc.) per metric ton product. In Asian or some European countries, the effluent can be discharge to ocean water with some treatment, say removing Ammonia, solid particles etc. but Na2SO4 still in the discharge effluent. In North America, the effluent is not allowed to discharge without removing Na2SO4. The effluent treatment itself is obviously a big project on capital investment and it is also expensive to operate.
Diagram 1, Source: SPI
SPI’s proposal is a close loop operation for producing precursors for the high nickel-based cathode materials. The process is environmental friendly and does not generate effluent at all. The advantages of the process are not only effluent free but also a low cost process, secured raw materials supply for North American customers. It saves energy and reduces GHG emission compared to traditional precursor production process.
Diagram 2, Source: SPI