The Effect of K-doping on Activation in Co-Free Li-Rich Cathodes.

The activation mechanism of Li-rich cathode has been discussed for many years, yet there is still debate on different theories. Potassium doping can assist the investigation on activation mechanism through its unique function in terms of blocking TM migration during activation.   K-doping works by occupying Li sites even after Li has been extracted, increasing stability by blocking transition metals from migrating into these sites, which can help us distinguish the pathway of activation.

On the disparity in reporting Li-rich layered oxide cathode materials.

Lithium-rich layered oxides are considered one of the most promising cathode materials for next generation lithium-ion batteries due to their extraordinary specific capacity of over 280 mA h g and superior energy density of over 1000 W h kg. Despite the excellent performance, LRLOs still suffer from low Coulombic efficiency, serious capacity/voltage decay upon cycling, voltage hysteresis, short lifespan, and poor rate capability. Driven by the thirst for high-energy-density battery technologies, various strategies have been developed to address these issues with great progress being achieved in the past several years.