Development of three-dimensional flexible binder-free core-dual shell electrodes via atomic layer deposition of synergistic metal oxide nanocomposites for lithium-ion batteries

Abstract

The development of three-dimensional (3D) electrode in lithium-ion battery aims to satisfy emerging applications in pursuit of high energy density and power density. Herein, a tunable core-dual shell 3D electrode is demonstrated by atomic layer deposition (ALD) of nanocomposite metal oxides on the surface of TiO2 nanorod (NR), hydrothermally grown on the carbon cloth (CC) without binders. The growth of one-dimensional TiO2 NR on CC mainly constructs the stable 3D framework in the electrode, which ensures a higher surface area to facilitate the electrolyte access and electrochemical reaction. The influence of nanocomposite metal oxides composed of ZnO and TiO2 as the dual shell of TiO2 NR on 3D electrode performance is systemically explored by a series of different ALD cycles. As a proof of concept, the enhancement of 51% and 40%, respectively, in the reversible capacity after 100 charge-discharge cycles and high rate performance at 3 A g−1 can be achieved in the 3D electrode with ALD growth of dual shell in comparison with the uncoated baseline. Such improvements mainly result from the synergistic effect of nanocomposite metal oxides with optimally individual thickness, enabling to further optimize the electrochemical performance and structural stability of 3D electrodes upon cycling.