Self-assembled three-dimensional flower-like ZnO encased by carbon toward stable lithium metal anode

Abstract

The carbon-encased flower-like ZnO was synthesized through a facile hydrothermal method, then followed with carbonization (ZnO@C), and for the first time utilized as a host material to facilitate uniform deposition and dissolution of lithium by taking advantage of the lithiophilic nature of ZnO. Flower-like ZnO with hierarchically porous structures and large specific surface area could provide abundant sites for regulated lithium deposition and simultaneously inhibit lithium dendrite growth. When tested in symmetric cells, the ZnO@C-500 electrode could maintain stable cycling at 1.0 mA cm⁻² for over 3000 h with a low overpotential of 13 mV and display satisfactory rate performance. When coupled with LiFePO₄ cathode, the full cell could still hold a high specific capacity of 103 mAh·g⁻¹ after 300 cycles at 1 C.