Mechanical Pulverization of Co-Free Nickel-Rich Cathodes for Improved High-Voltage Cycling of Lithium-Ion Batteries

Nickel-rich cathode materials are slated to become the next commercial cathode for electric vehicles, however their long-term cycle life retention and air stability remain a barrier to the introduction of these lower cost, higher capacity materials. Surface reactivity and mechanical degradation and at high voltage remain two issues that stand in the way of the material’s commercialization. While surface treatments have shown great promise in reducing surface reactivity, mechanical degradation or “cathode cracking” persists. In the presented work, NMA cathode materials are pulverized into their primary particle constituents and coated with lithium phosphate via solution-based chemistry with varying concentrations of phosphoric acid. The cathodes are characterized using EDX, XPS, TEM, EIS and electrochemical cycling. After 100 cycles, the coated NMA cathodes show delayed voltage decay, and double the discharge capacity in full cells during high voltage cycling.