A silver-doped lignin porous carbon nanosheet and its preparation method and application in supercapacitor electrode materials

Abstract

The invention belongs to the technical field of biomass carbon materials, and discloses a silver-doped lignin porous carbon nanosheet, a preparation method thereof and an application in supercapacitor electrode materials. The preparation method of the present invention performs layer-by-layer self-assembly of sulfonated lignin, silver salt and oxalate in a selective solvent to prepare a layer-by-layer self-assembled silver / lignin / oxalate composite, which is carbonized and pickled , to obtain silver-doped lignin porous carbon nanosheets. The invention provides silver-doped lignin porous carbon nanosheets prepared by the above method, the specific surface area of ​​which is 200-1000m 2 / g, micropore specific surface area 100~300m 2 / g, mesopore specific surface area 100~700m 2 / g, pore size 0.5~20nm, pore volume 0.5~1.5cm 3 / g; has excellent conductivity and can be applied to supercapacitor electrode materials, thereby greatly improving the specific capacitance and rate performance of supercapacitor electrode materials.

Description

technical field [0001] The invention belongs to the technical field of biomass carbon materials, and in particular relates to a silver-doped lignin porous carbon nanosheet, a preparation method thereof, and an application in supercapacitor electrode materials. Background technique [0002] The increasing depletion of traditional fossil energy and the increasingly severe environmental pollution have put forward new requirements for the development and utilization of green new energy. Electrochemical energy storage devices play an important role in the development of green and sustainable energy storage and conversion technologies. As a new type of energy storage device between traditional physical capacitors and secondary batteries, supercapacitors are widely used in portable electronic devices and electric vehicles due to their high power density, fast charge and discharge, long cycle life and wide applicable temperature range. Automotive and other fields have attracted wid...

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Problems solved by technology

The template method can prepare porous carbon materials with concentrated pore size distribution, but the pore structure distribution of the prepared porous carbon is relatively single, and the preparation process is relatively complicated and the cost is high

[0007] Lignin porous carbon prepared by chemical activation method and template method has high specific surface area, but still has the problem of poor conductivity

The conductivity of lignin porous carbon can be improved by doping with N, S, B and other elements or doping with conductivity enhancers. Zhang et al. used bioethanol lignin as carbon precursor and prepared nitrogen-doped porous carbon by hydrothermal carbonization. Interconnected hierarchical porous carbon with high conductivity, this method takes a long time and the nitrogen content of the product is difficult to control (ACS applied materials&interfaces,2016,8(22):13918-13925)

Literature (Zhang Wu. Research on biomass-based nitrogen-doped coke and porous carbon electrode materials. Hunan University, 2017.) Sodium lignosulfonate was used as the carbon source, graphene was used as the conductivity enhancer, and p-phenylenediamine was used as the nitrogen source , a porous coke material with high conductivity was prepared by one-step low-temperature pyrolysis. This method requires the preparation of graphene by oxidation-reduction method, which is complicated in process and high in production cost.

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