sc9b04416_si_001.pdf (2.88 MB)
Hierarchical Nanosheet Arrays of Metal Oxides Guide Uniform Deposition for Lithium Anodes
journal contribution
posted on 2019-12-11, 15:06 authored by Zhe Wang, Dan Cheng, Hua He, Kebin ZhouLithium metal, regarded as the “Holy Grail”
of lithium
battery anodes, has been considered as the most promising material
for high-energy density rechargeable batteries. However, its practical
application has been hindered by the uncontrolled dendrite growth
of the lithium metal during charge–discharge cycles. Guiding
uniform deposition of lithium during cycling is an effective route
to solve the problem. In this contribution, nanosheet arrays of lithiophilic
metal oxides with a hierarchical structure, that is, primary vertical
thin arrays coupled with secondary grid-like ones, were constructed
on a Cu current collector to regulate lithium nucleation and growth.
It was found that the primary vertical thin nanosheet arrays could
reduce the current density and provide adequate lithiophilic sites
with a lower nucleation barrier, while the secondary grid-like nanosheet
arrays offered facile Li-ion diffusion and a large volume for lithium
deposition. Owing to the uniform deposition behavior and stable electrode
structure, the modified Li anode showed a high Coulombic efficiency
of 98% for 230 cycles. When the structured anode was assembled with
a LiFePO4 cathode, the full cell presented markedly enhanced
capability retention and improved rate performance.