Abstract
Si is essential as an active material in Li-ion batteries because it provides both high charge and optimal cycling characteristics. A composite of Si particles, Cu particles, and pure H2O was realized to serve as an anode active material and optimize the charge–discharge characteristics of Li-ion batteries. The composite was produced by grinding using a planetary ball mill machine, which allowed for homogenous dispersion of nanoscale Cu3Si as Si–Cu alloy grains and nanoscale Si grains in each poly-Si particle produced. Furthermore, some Si particles were oxidized by H2O, and oxidized Si was distributed throughout the composite, mainly as silicon monoxide. As a result, each Si particle included silicon monoxide and conductive Cu3Si materials, allowing for effective optimization of the recharging and charge-discharge characteristics. Thus, a new and simple process was realized for synthesizing a Si active material composited with silicon oxides, including silicon monoxide. This Si-rich conductive material is suitable as an anode for Li-ion batteries with high charge and optimized cycling properties.
Highlights
Owing to its high theoretical Li storage potential of about 4000 mAh g−1 [1], Si is one of the most attractive anode materials for Li-ion batteries (LIBs)
We developed a grinding method in which Si particles and Cu particles as a conductive material were ground with pure H2O in the mill pots of a planetary ball mill (Fritsch Pulverisette-7) to produce a composite material
The composite particles, which are similar in size to the bare Si particle, appear to have small particles attached along their circumferences
Summary
Owing to its high theoretical Li storage potential of about 4000 mAh g−1 [1], Si is one of the most attractive anode materials for Li-ion batteries (LIBs). Si undergoes frequent drastic changes in volume during charge-discharge cycling, causing degradation of Si materials and drastically decreasing ionic and electronic conductivities, which has prevented Si anodes from being utilized in Li-ion secondary batteries [2]. This study considers a technique that maintains the high ionic and electronic conductivities of Si by preventing cracking during volume changes, with as little effect as possible on the capacity of the material. The atomic distribution of Si, oxides, and Cu was measured using energy dispersive X-ray spectroscopy (EDX; Hitachi High-Technologies Corporation, Japan). Electron energy-loss spectroscopy (EELS; Hitachi High-Technologies Corporation, Japan) at 200 kV was used to measure the distribution of oxides in the composite at a resolution of 0.5 eV. The electrochemical performance of these two-electrode test coin cells was evaluated using a constant current charge-discharge cycling test in the voltage range of 1.6–4.2 V, with a current density of 0.1 mA cm−2 at room temperature
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
