  The electrification revolution in automobile industry and others demands
annual production capacity of batteries at least on the order of 102 gigawatts
hours, which presents a twofold challenge to supply of key materials such as
cobalt and nickel and to recycling when the batteries retire. Pyrometallurgical
and hydrometallurgical recycling are currently used in industry but suffer from
complexity, high costs, and secondary pollution. Here we report a
direct-recycling method in molten salts (MSDR) that is environmentally benign
and value-creating based on a techno-economic analysis using real-world data
and price information. We also experimentally demonstrate the feasibility of
MSDR by upcycling a low-nickel polycrystalline LiNi0.5Mn0.3Co0.2O2 (NMC)
cathode material that is widely used in early-year electric vehicles into
Ni-rich (Ni > 65%) single-crystal NMCs with increased energy-density (>10%
increase) and outstanding electrochemical performance (>94% capacity retention
after 500 cycles in pouch-type full cells). This work opens up new
opportunities for closed-loop recycling of electric vehicle batteries and
manufacturing of next-generation NMC cathode materials.
