High-Energy Cathodes via Precision Microstructure Tailoring for Next-Generation Electric Vehicles

초록

With the prevalence of electric vehicles (EVs), Ni-rich layered cathodes have been extensively studied to increase their capacities. The use of a Ni-rich core encapsulated by a shell with concentration gradients (CSG) is the only field-proven strategy that is able to tap the potential capacity of Ni-rich cathodes. Herein, it was demonstrated that doping a CSG cathode with an average composition of Li[Ni0.9Co0.05Mn0.05]O2 with 0.5 mol% Sb substantially improved its cycling stability while providing manufacturing flexibility. Sb doping allowed precise tailoring of the cathode microstructure through the retardation of cation migration and the inhibition of coarsening by pinning particle boundaries. The Sb-doped CSG cathode retained ∼80% of its initial capacity for 2500 cycles, while the pristine CSG90 cathode showed similar capacitive deterioration over only 1500 cycles. The proposed Sb-doped CSG90 cathode for use in EVs represents an ideal high-energy-density cathode with a composition engineered to maximize capacity; its modified microstructure ensures a long battery life and ease of manufacturing, enabling cost reduction.

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