Preparation method and application of carbon-nitrogen doped ternary composite metal oxide based on prussian blue frame material

Abstract

The invention provides a preparation method of a carbon-nitrogen doped ternary composite metal oxide based on a prussian blue frame material. The preparation method comprises the steps of preparing the prussian blue frame material and calcining the obtained prussian blue frame material, so as to obtain the carbon-nitrogen doped ternary composite oxide. Additionally, the invention also provides application of the prepared carbon-nitrogen doped ternary composite metal oxide serving as a negative material of a lithium ion battery. With adoption of the prepared carbon-nitrogen doped ternary porous composite metal oxide, the change of volume of the negative material in a charging / discharging process can be effectively relieved, and the electronic conductivity of the material is improved, therefore, the reversible specific capacity and the cycling stability of the material can be effectively improved; the main starting material such as the prussian blue complex can be prepared by green methods such as a microwave reaction of water or an ethanol medium, so that the preparation process is simple, and the yield is high; meanwhile, the material contains three different metals, so that the properties of the composite material can be synergetic and complementary through careful selection.

Description

technical field [0001] The invention belongs to the field of electrochemistry, in particular to a method for preparing a carbon-nitrogen-doped ternary composite metal oxide based on a Prussian blue frame material and the application of the ternary composite metal oxide as a negative electrode material for a lithium-ion battery . Background technique [0002] Anode materials are one of the key factors determining the performance of lithium ion batteries (Lithium Ion Batteries, LIBs). With the widespread use of lithium batteries, anode materials have attracted more and more attention. In recent years, China, Japan and many other countries have invested a lot of manpower and material resources in research and development of lithium batteries, which has greatly improved the performance of existing negative electrode materials. At present, commercial lithium battery anode materials mainly include: ① graphite-like carbon materials, divided into natural graphite and artificial gra...

AI Technical Summary

Problems solved by technology

Other non-graphite anode materials, such as hard carbon materials have low initial efficiency and high cost; soft carbon materials have large initial irreversible capacity and low volumetric energy density; high-capacity silicon-based anode materials have first-week efficiency, cycle performance, and rate performance Both still need to be improved, volume expansion and other issues urgently need to be solved

[0004] Although nano-metal oxides (M x o y , M=Fe, Co, Ni, Cu, Mn, Mo, etc.) As a new generation of high-capacity negative electrode materials for lithium-ion batteries, there are many advantages (such as high charge and discharge capacity), which have attracted more and more attention. However, due to the constant volume change during charging and discharging, the diffusion of lithium ions is slow, and its capacity decays rapidly with the increase of the number of cycles.

On the other hand, the two-step preparation method of metal oxides currently commonly used is relatively complicated, requires high equipment, and is difficult to control the shape and size, so it is not suitable for large-scale production.

Obviously, the inherent shortcomings of transition metal oxides have seriously hindered their application in lithium-ion battery materials, and their commercialization is still relatively long compared with graphite-based carbon materials.

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