Phosphorus Coating Composition for Low-Resistance Cathode Particles

The patent changes the chemical composition parameters of the coating film by using phosphorus compounds with specific Li/P ratio (CLi/CP ≤ 2.5) instead of conventional Li3PO4. This parameter change reduces initial resistance while maintaining protective functions, directly resolving the contradiction between protection and resistance.

The patent employs composite coating materials containing phosphorus compounds combined with specific ratios of lithium compounds. This composite approach creates a coating film that simultaneously achieves low initial resistance and effective protection, overcoming the limitations of single-material coatings like Li3PO4.

The patent changes the material composition from niobium compounds to phosphorus compounds with controlled Li/P ratios. This parameter change achieves both low initial resistance and minimal resistance increment after endurance tests, resolving the time-dependent performance contradiction.

The patent uses phosphorus compounds that form stable, durable coating films replacing niobium compounds. Although phosphorus compounds may have different initial properties, they provide sustained performance over time with minimal resistance increment, effectively addressing the duration-based contradiction.

The patent optimizes the CLi/CP ratio to be 2.5 or less, finding the optimal balance point where both adequate Li-ion conductivity (low initial resistance) and high covering rate are achieved. This precise parameter optimization resolves the contradiction between conductivity and coverage.

The patent applies phosphorus compounds with controlled lithium content to achieve sufficient Li-ion conductivity without excessive lithium that would reduce covering rate. This partial action approach maintains the right balance between conductivity requirements and coverage efficiency.