Shichao Zhang

Nickel Nanocone‐Array Supported Silicon Anode for High‐Performance Lithium‐Ion Batteries

The development of Li-ion batteries with high capacity, long lifespan, and fast charge/discharge rates is of great technological importance for future portable electronics, power tools, electric and hybrid vehicles, and renewable energies. [ 1–3 ] Silicon is a particularly appealing anode material for Li-ion batteries because of its high theoretical capacity of 4200 mAh g − 1 [ 4 ] and it has been the subject of extensive research efforts. [ 5 , 6 ] However, lithium alloying and de-alloying with Si are accompanied by an enormous volume change ( > 300%), which induces severe pulverization and electrical disconnection from the current collector. [ 7 ] This structural and electronic degradation thereby leads to drastic and fast capacity fading and hindrance of practical implementation. To overcome these drawbacks, one effective approach is to design powder-based composites (e.g., a Si-metal active/inactive matrix concept), [ 8 , 9 ] preferably Si-carbon composites which have been investigated for many years. [ 10–13 ] Previous research has shown improvement of the electrochemical performance of Si-based anodes but only to a limited extent. [ 6 ]

A Three-Dimensional Cellular Copper Prepared by Multiple-Step Electrodeposition

A method of preparing three-dimensional copper cellular architecture by multiple-step electrodeposition without any polymer framework is reported in this article. Simultaneously, the physical properties and strengthening mechanism of this material in the second electrodeposition was also investigated by means of scanning electron microscopy, mechanical testing, and linear sweep voltammetry. During this process, a series of positive internal structural changes occurred inside the first deposited copper foam, which led to the improvement of mechanical strength and bonding force with the substrate.