Recycling: Research On The Preparation Of Energy Storage Carbon Materials From Straw And Cotton Stalk

The Institute of Agricultural Environment and Sustainable Development of the Chinese Academy of Agricultural Sciences has learned that the team of the Institute for Clean Transformation and High value Utilization of Planting Wastes has revealed the synthesis path and regulation mechanism of the preparation of energy storage carbon materials through polymerization modification of straw cotton stalk tar, which provides a new perspective and new method for high value utilization of straw cotton stalk. The relevant research results were recently published in the academic journal Biochar.

In 2022, China will produce 865 million tons of crop straw and cotton stalk. Promoting the high value utilization of straw and cotton stalk is an important measure to improve the agricultural ecological environment and accelerate the green and low-carbon development of agriculture. Pyrolysis technology can transform straw into biochar, pyrolysis gas, pyrolysis tar and other products, and promote the high-value utilization of straw and cotton stalk out of the field. Among them, pyrolysis tar has the characteristics of high carbon content, low ash content and easy polymerization, which is suitable for regulating and synthesizing porous carbon materials. However, the composition of tar is complex, and the mechanism of carbon formation by polymerization and pore regulation are still unclear.

Yao Zonglu, the corresponding author of the paper and a researcher at the Institute of Agricultural Environment and Sustainable Development of the Chinese Academy of Agricultural Sciences, introduced that this research proposed a synthetic strategy of preparing porous energy storage carbon materials by tar polymerization and synergistic activation of nitrogen doping, and found that the synergistic effect of urea and potassium hydroxide played an important role in nitrogen doping and the formation of micro mesopores, The prepared energy storage carbon material has excellent energy storage characteristics. The team tested the supercapacitor device assembled with energy storage carbon materials prepared from tar, and the results showed that the highest specific capacitance of the device in the three electrode system was 309.5 farad/g. After 10000 cycles in the two electrode symmetrical system, the specific capacitance of its monopole still maintains 80.1% of the cycle characteristics, and its performance is significantly better than that of commercial activated carbon.

This study provides a new path and theoretical support for the high-value utilization of straw and cotton stalk. "If the technology of preparing energy storage carbon materials from straw and cotton stalk tar proposed in the research is industrialized, it may produce certain economic benefits," said Yao Zonglu.