Pomegranate-like gallium oxide nanospheres coated with nitrogen-doped carbon as an anode for lithium-ion batteries with an ultra-long cycle life

Ga-based materials have emerged as novel self-healing anodes that can spontaneously repair cracks during cycling. However, Ga-based alloying is limited by an unstable solid–electrolyte interphase (SEI) and severe aggregation resulting from the fluidity of Ga . In this study, Ga 2 O 3 nanoparticles of ∼20 nm were synthesized. By confining and separating the Ga 2 O 3 nanoparticles using doped carbon shells, Ga 2 O 3 @C with a pomegranate-like structure was successfully fabricated and used as an anode for ultra-long-life lithium-ion batteries. The carbon shell prevents aggregation of the lithium storage reaction product (Ga), provides better electrical conductivity , and forms a more stable SEI. The obtained Ga 2 O 3 @C anode exhibits a mixed lithium storage mechanism consisting of both diffusion-controlled and capacitive-controlled processes, with a pseudocapacitive contribution of up to 75.0 % at 1.0 mV s −1 . The accelerated electrochemical reaction kinetics and high pseudocapacitive contribution of Ga 2 O 3 @C help deliver excellent cycling stability and rate properties. The Ga 2 O 3 @C anode can retain a capacity of ∼297.4 mAh g −1 within 3000 cycles at a high current density of 2 A g −1 .