Preparation method and application of nitrogen-doped porous carbon negative electrode material

Abstract

The invention belongs to the technical field of carbon material preparation, belongs to the category of alkali metal ion secondary energy storage and relates to a method for preparing nitrogen-doped porous carbon from perinone nitrogen-containing polycyclic aromatic hydrocarbon as a carbon source and an application of the nitrogen-doped porous carbon as a negative electrode or positive electrode material for an alkali metal ion secondary battery. According to the method, perinone nitrogen-containing conjugated polycyclic aromatic hydrocarbon is firstly mixed with a template or an activator andthermal decomposition carbonization is carried out at the temperature within a certain range to obtain a nitrogen-doped porous carbon negative electrode or positive electrode material. By adopting the perinone nitrogen-containing conjugated polycyclic aromatic hydrocarbon with large molecular weight as the carbon source, the loss of a nitrogen element in a thermal treatment process can be reduced, high-proportion nitrogen doping in the porous carbon is effectively achieved and electrochemical oxidation reduction sites are effectively increased. According to the method, the specific surface area of the porous carbon can be adjusted and controlled through the carbon source screening, thermal treatment carbonization temperature and the mass ratio of the template or the activator, the chargeexchange interface is increased and high energy storage is effectively achieved. The material has the advantages that (1) the structure is abundant and the perinone material is cheap and available; and (2) the material has relatively high energy density, magnification power density and cycling stability.

Description

technical field [0001] The invention specifically relates to a preparation method of nitrogen-doped porous carbon negative electrode materials, and relates to the steps and raw materials used in the preparation process of these materials. technical background [0002] In the electronic information age, people's demand for portable, high-power, and highly intelligent power supply equipment is increasing day by day, making high-performance energy storage systems a common topic in the field of energy research and application that needs to be realized urgently. Driven by multiple objective forces such as the reduction of traditional energy reserves, global warming, and the increasing protection of the living environment, the way of energy production and use is changing to a new type of clean energy. Nowadays, the emergence of high-efficiency secondary energy storage devices and key technologies and materials provides the preferred option for convenient energy and power support f...

AI Technical Summary

Problems solved by technology

The maximum theoretical chemical lithium intercalation capacity of petroleum coke, which was first used as the negative electrode material for lithium intercalation, is LiC 12 , the electrochemical specific capacity is 186mAh / g, and there are shortcomings such as volume expansion and reduced battery life during lithium intercalation that limit its further development; traditional graphite negative electrode materials are prone to damage to the layered structure due to the process of intercalation and desorption of lithium ions, which affects the cycle life of the battery. The ultimate product of interlayer lithium intercalation is LiC 6 , its actual specific capacity (~270mAh / g) is lower than the theoretical value (372mAh / g), and the lithium intercalation process on the vertical graphite layer is difficult, which affects the rate cycle performance and limits its application in the new generation of lithium-ion batteries

Artificial graphite and interphase carbon microspheres with similar reversible specific capacity can only be obtained through graphitization heat treatment in an ultra-high temperature furnace at 2400 °C and above, and the cycle life is relatively long. The main disadvantage is that the specific capacity potential is insufficient and the high-cost ultra-high temperature The furnace preparation process makes it more expensive to manufacture than graphite carbon

In addition, new carbon materials such as carbon nanotubes and graphene with special three-dimensional, two-dimensional flexible structure, good electrical conductivity and thermal conductivity have brought new opportunities to the development of lithium-ion batteries, but there are also low Insufficient Coulombic efficiency, hysteresis voltage, etc., are not suitable for direct use as negative electrode materials, and require appropriate structural modification and heteroatom-doped amorphization treatment

Images