Zinc–Carbon Battery Recycling for Investigating Carbon Materials for Supercapacitor Applications

In this paper, carbon materials, including graphene nanosheets and carbon nanoparticles, were prepared from spent zinc–carbon batteries by the following two simple methods: electrochemical exfoliation and ultrasonication. Here, graphene nanosheets were synthesized by electrochemical exfoliation in 0.5 M H₂SO₄ by using a direct current power supply with two carbon rods from spent zinc–carbon batteries. Carbon nanoparticles were prepared by fast ultrasonication in a low-cost, green solution of DI water and ethanol. Graphene nanosheets in this study have high quality, large scale, and good electrochemical ability, while carbon nanoparticles have a unique nanosize and a good specific surface area. These carbon materials were applied for electrochemical measurements for supercapacitor studies and showed excellent stability at different temperatures. Moreover, electric double-layer capacitor devices based on graphene nanosheets and carbon nanoparticles were also used in electrochemical studies with strong stability and good electrochemical capability.