Graphene-based nano flower-shaped silicon-copper alloy electrode material and its preparation method and application

Abstract

A graphene-based nano-flower-shaped silicon-copper alloy electrode material in the field of electrochemical energy technology and its preparation method and application. Using electrochemical deposition and etching technology, firstly prepare nano-flower-shaped copper oxide on a flexible graphene substrate, and introduce it in the next step. Silicon provides a good template; then deposited silicon by plasma-enhanced chemical vapor deposition technology and reduced copper oxide, so that copper can be combined with external silicon through reduction and diffusion to form a silicon-copper alloy, which greatly improves the silicon-copper alloy. The conductivity provides a good and fast channel for lithium intercalation and delithiation during the charging and discharging process of the lithium battery, and improves the cycle performance of the battery.

Description

technical field [0001] The invention relates to a technology in the field of electrochemical energy, in particular to a graphene-based nano flower-shaped silicon-copper alloy electrode material and its preparation method and application. Background technique [0002] Lithium-ion batteries are also called rocking chair batteries. This kind of battery is like a rocking chair. The process of reversible intercalation and deintercalation is the process of charging and discharging lithium-ion batteries. [0003] Since the lithium-ion battery was developed and launched by Sony in 1973, its commercial negative electrode material has been using traditional graphite electrodes, but the theoretical specific capacity of graphite electrodes is only 372mAh / g, which is not enough to meet the needs of existing high-performance electronic devices. Therefore, It is necessary to develop a new type of high specific capacity electrode material to replace it, Li 4.4 The silicon anode material w...

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Problems solved by technology

[0004] However, silicon materials also have many disadvantages that need to be overcome

First of all, as a semiconductor material, silicon has a lower electrical conductivity than other metals and carbon-based materials, and a suitable method is needed to improve its own electrical conductivity, so as to provide a faster channel for lithium ion intercalation and extraction; In the process, with the intercalation and extraction of lithium ions, a very large volume change will occur, and the maximum volume will exceed 300% of the original, which will bring huge stress to the negative electrode structure, resulting in a decrease in the stability of the negative electrode structure, fragmentation of the electrode, and gradually Pulverization, structural collapse, and increased contact resistance eventually lead to a decrease in cycle performance; at the same time, this fragmentation will also lead to the generation of more non-conductive SEI (Solid electrolyte interphase, solid electrolyte interphase film), which will aggravate the corrosion and energy loss of silicon materials. attenuation, eventually leading to reduced battery performance

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