A facile and generic method to improve cathode materials for lithium-ion batteries via utilizing nanoscale surface amorphous films of self-regulating thickness

摘要: As a facile and generic surface modification method, unique class of amorphous films (SAFs) is utilized to significantly improve the rate performance cycling stability cathode materials for lithium-ion batteries. These nanoscale SAFs form spontaneously uniformly upon mixing annealing at thermodynamic equilibrium, they exhibit self-regulating or “equilibrium” thickness due balance attractive repulsive interfacial interactions acting on films. Especially, spontaneous formation Li3PO4-based has been demonstrated in two proof-of-concept systems, LiCoO2 LiMn1.5Ni0.5O4, which have an equilibrium ∼2.9 nm ∼2.5 nm, respectively. At high discharge 25 C, these capacity by ∼130% ∼40% Furthermore, reduce fading both LiMn1.5Ni0.5O4. elevated temperature 55 °C, can help maintain ∼90 mA h g−1 high-voltage material LiMn1.5Ni0.5O4 after 350 cycles relatively charge–discharge 1 C. Further mechanistic studies suggest that charge transfer resistance suppress growth solid–electrolyte interphase. This method be broad range anode materials. A framework proposed, used guide future experiments other systems.