A thermodynamically guided interfacial precipitation strategy for high-power and long-life Ni-rich layered cathodes

Interfacial engineering is crucial for developing high-performance Ni-rich layered cathodes for lithium-ion batteries. Here, we introduce an interfacial precipitation (IP) strategy, guided by first-principles calculations, to create a functionally graded cathode during precursor synthesis. Based on thermodynamic principles of bulk insolubility and phase separation kinetics, we achieved the selective precipitation of Co onto the surface of a Ni-rich hydroxide precursor. Upon high-temperature lithiation, this engineered precursor spontaneously forms a unique, bifunctional Co-rich spinel-like layer on the final LiNi0.88Co0.06Mn0.06O2 (NCM) cathode. This architecture suppresses detrimental Li/Ni cation mixing and protects the active material. Consequently, the IP-driven NCM cathode demonstrates vastly superior rate capability, delivering 140.8 mA h g−1 at 5C, compared to 112.9 mA h g−1 for its conventionally prepared counterpart. This enhancement is attributed to significantly lower charge-transfer resistance and faster kinetics. Remarkably, in a full-cell configuration, the IP-driven NCM cathode maintains 81.5 % capacity after 1000 cycles at an aggressive 5C rate. This work presents a thermodynamically driven, scalable strategy for designing advanced cathodes with exceptional high-power performance and stability.