From NMC to NMC – Challenges of Direct Recycling

Since 1991, when SONY introduced lithium-ion batteries, we have been living in a "portable era". Today, we are surrounded by small mobile devices like laptops, cellphones, smartwatches, ear pods, and power banks. In 2021, EVs constituted almost 9% of the total automotive market share worldwide 1 . EV sales in Europe have increased by 70% with 2.3 million cars sold, thanks to a new regulation mandating 100% CO 2 emission reduction for new cars and vans from January 1st, 2035 2 . Several automakers, including Volkswagen, Ford, and Toyota, have announced plans to electrify at least 50% of their fleets by the end of this decade. Before electric cars become feasible, we need to develop efficient recycling methods for spent batteries. Accumulating battery waste is unsustainable. The battery industry faces challenges like rising material costs and geopolitical factors, such as ore mining in the Central African Copper Belt and the recovery of raw critical materials 3 . Efficient resource management is a top priority in the European Union, with both EU Parliament regulations and grassroots initiatives like 6R being widely implemented. Recycling of lithium-ion batteries involves the recovery of valuable metals such as cobalt, nickel, and lithium. There are two main methods for recycling: pyrometallurgical (heat treatment and smelting) and hydrometallurgical (acid leaching, bioleaching, solvent extraction, chemical precipitation, and electrochemical processes). Direct recycling is a cost-effective method that aims to restore the capacity and property losses of active materials through cycling. Recovered cathode material can be restored to its original performance by re-lithiation or upcycling into a modern composition, such as turning LCO into NMC 4,5 . Solid-state sintering is the simplest method for direct recycling, however, a universal protocol for all cathodes is not available. Therefore, distinct healing chains for each active cathode must be established before being applied to mixed cathodes and optimized. In my upcoming presentation, I will discuss a novel method for recycling LiNiMnCoO 2 , a significant battery waste material. We have developed an environmentally friendly technology that can extract lithium from degraded NMC powders, that can be further lithiated and reused as active electrode powder, while the extracted lithium can then be converted into hydroxide or carbonate and reused as a precursor for the synthesis of fresh NMC or recycled NMC precurso