Silicon cathode and preparation method thereof and Li-ion secondary battery comprising silicon cathode

Abstract

The invention relates to a silicon cathode of a Li-ion secondary battery. The silicon cathode comprises a conducting matrix and a material layer, wherein the material layer comprising a silicon-contained material layer and a titanium nitride layer is adhered on the surface of the conducting matrix, the silicon-contained material layer is adhered on the conducting matrix and the titanium nitride layer is adhered on the silicon-contained material layer. The invention also provides a preparation method of the silicon cathode and a Li-ion secondary battery comprising the silicon cathode. The Li-ion secondary battery comprising the silicon cathode prepared by the invention has higher discharging specific capacity, higher first-time charge-discharge efficiency and favorable circulation performance. The silicon cathode provided by the invention can realize commercialization application of the Li-ion secondary battery with low cost.

Description

technical field [0001] The present invention relates to a negative pole of a battery, a preparation method thereof, and a battery using the negative pole. Specifically, the present invention relates to a silicon negative pole of a lithium-ion secondary battery, a preparation method thereof, and a lithium-ion secondary battery using the silicon negative pole. . Background technique [0002] Most of the current commercialized lithium-ion batteries use lithium transition metal oxide / graphite system as the active material. Although the active material of this type of system has excellent electrochemical performance, its own lithium storage capacity is low, especially the carbon-based negative electrode active material. The theoretical capacity is only 372mAh / g. Such a low capacity is difficult to meet the miniaturization development of various portable electronic devices and the demand for large-capacity and high-power chemical power sources for electric vehicles. Therefore, a ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the disadvantages of the battery prepared by the existing silicon negative electrode, such as unsatisfactory discharge specific capacity, unsatisfactory initial charge and discharge efficiency, and cycle performance, and cannot be commercially applied to lithium-ion batteries, and provide a low-cost, capable Commercially applied silicon negative electrode for lithium-ion batteries and its preparation method, lithium-ion secondary electrodes prepared from the silicon negative electrode with high discharge specific capacity, first-time charge-discharge efficiency and good cycle performance, and their preparation methods