6 research outputs found
Balancing the Ion/Electron Transport of Graphite Anodes by a La-Doped TiNb<sub>2</sub>O<sub>7</sub> Functional Coating for Fast-Charging Li-Ion Batteries
A functional coating
layer (FCL) is widely applied in fast-charging
lithium-ion batteries to improve the sluggish Li+ transport
kinetics of traditional graphite anodes. However, blindly increasing
the Li+ conductivity for FCL reduces the overall electron
conductivity of the anodes. Herein, we decoupled the effect of La-doping
on TiNb2O7 (TNO) in terms of the phase evolution,
Li+/electron transport, and lithiation behavior, and then
proposed a promising La0.1TNO FCL with balanced Li+/electron transport for a fast-charging graphite anode. By
optimizing the doping concentration of La, more holes are introduced
into the TNO as electron carriers without causing lattice distortion,
thus maintaining the fast Li+ diffusion channel in TNO.
As a result, the graphite with La0.1TNO FCL delivers an
excellent capacity of 220.2 mAh g–1 (96.3% retention)
after 450 cycles at 3 C, nearly twice that of the unmodified one