Improvement in electrochemical properties using SiO-C stacking layer composite for the negative electrode of Li-ion batteries

The stacking layer electrode with a carbon black layer adds on a silicon monoxide (SiO) film is developed for lithium-ion batteries. The electrode is composed of a dense amorphous SiO film with a thickness of 70 nm on a stainless substrate, and an aggregate layer of carbon black particles with a diameter of 40 nm. The electro-chemical properties show reversible charge-discharge curves, except the 1st charge process. In the reversible reactions, the maximum charge capacity is 2188.8 mAh/g at the current density of 0.1C. The capacity retention rate and Coulomb efficiency are 94 and 99.7 % for 500 cycles, respectively. After the examination, the SiO surface shows cracks and divided into 1 mu m scale domains, though the peeling area is less than a few percent. The charge-discharge reactions bring about large volume changes, however the related degradation is suppressed. The electrochemical properties of the as-deposited SiO film electrode shows the maximum charge capacity of 976 mAh/g and the capacity retention rate of 71 % after 50 cycles. The capacity is nearly half of that of the stacking layer electrode, and the cycle performance is slightly degraded.

Automated summary

A stacking layer electrode with a carbon black layer on a silicon monoxide (SiO) film has been developed for lithium-ion batteries. The electrode consists of a dense amorphous SiO film and a layer of carbon black particles. The electro-chemical properties exhibit reversible charge-discharge curves, and the capacity retention rate and Coulomb efficiency are high for 500 cycles. The as-deposited SiO film electrode shows lower capacity and slightly degraded cycle performance.