Atomic layer deposition of ZnO on carbon black as nanostructured anode materials for high-performance lithium-ion...

Although zinc oxide (ZnO), a low-cost and naturally abundant material, has a high theoretical specific capacity of 987 mA h g^-1 for hosting lithium ions, its application as an anode material has been hindered by its rapid capacity fading, mainly due to a large volume change (around 228%) upon repeated charge-discharge cycles. Herein, using carbon black (CB) powder as a support, ZnO-carbon black (denoted as ZnO-CB) nanocomposites were successfully fabricated using the atomic layer deposition (ALD) method. This method was able to produce strong interfacial molecular bindings between ZnO nanoclusters and the carbon surface that provide stable and robust electrical contact during lithiation and delithiation processes, as well as ZnO nanoclusters rich in oxygen vacancies (OVs) for faster Li-ion transport. Overall, the nanocomposites were able to deliver a high discharge specific capacity of 2096 mA h g^-1_ZnO at 100 mA g^-1 and stable cyclic stability with a specific capacity of 1026 mA h g^-1_ZnO maintained after 500 cycles. The composites also have excellent rate capability, and a reversible capacity at a high 1080 mA h g^-1_ZnO at 2000 mA g^-1. The facile but unique synthesis method demonstrated in this work for producing nanostructures rich in OVs and nanocomposites with strong coupling via interfacial molecular bindings could be extended to the synthesis of other oxide based anode materials and therefore could have general significance for developing high energy density lithium ion batteries.