Designing a thick electrode with
appropriate mass loading is a
prerequisite toward practical applications for lithium ion batteries
(LIBs) yet suffers severe limitations of slow electron/ion transport,
unavoidable volume expansion, and the involvement of inactive additives,
which lead to compromised output capacity, poor rate perforamnce,
and cycling instability. Herein, self-supported thick electrode composed
of vertically aligned two-dimensional (2D) heterostructures (V-MXene/V2O5) of rigid Ti3C2TX MXene and pliable vanadium pentoxide are assembled via an ice crystallization-induced strategy. The vertical channels prompt
fast electron/ion transport within the entire electrode; in the meantime,
the 3D MXene scaffold provides mechanical robustness during lithiation/delithiation.
The optimized electrodes with 1 and 5 mg cm–2 of
V-MXene/V2O5 respectively deliver 472 and 300
mAh g–1 at a current density of 0.2 A g–1, rate performance with 380 and 222 mAh g–1 retained
at 5 A g–1, and reliability over 800 charge/discharge
cycles.