Preparation and electrochemical properties of nitrogen-doped starch hard carbon anode materials for lithium-ion battery

Here, we report the synthesis of hard carbon materials (CSHs) made from corn starch and their application as an anode in lithium-ion batteries. The study shows that the microstructure and electrochemical properties of CSHs are affected by nitrogen doping. It is found that nitrogen is embedded in the carbon layer with graphite nitrogen, pyridyl nitrogen, and pyrrole nitrogen, so that the surface morphology was changed and reduced the disorder of the materials. The electrochemical test results show that the introduction of nitrogen elements can increase the reversible capacity of the material, with the first discharge capacity reaching above 426.35 mAh g⁻¹, and the rate performance also improves. When melamine and pre-carbonized corn starch are carbonized at a mass ratio of 1:9, the obtained material has a reversible capacity of 122.04 mAh g⁻¹ at a rate of 2 C. During the carbonization process, the nitrogen in melamine is doped into the carbon materials, improving the electrochemical performance of the material.