Simple Synthesis of N-Doped Interconnected Porous Carbon from Chinese Tofu for High-Performance Supercapacitor and Lithium-Ion Battery Applications

The insatiable appetite for low-cost, high-energy, stabilized and miniaturized energy storage devices has become a hot social issue in the twenty-first century. In this study, Chinese Tofu, a very common and low-cost commercial product, was used to synthesize N-doped interconnected porous carbon materials (NICPs) via a low-budget method. The special features, such as the interconnected structure, ultrahigh surface area (2471 m2g−1), abundant macropores/mesopores and heteroatom dopant, cause NICPs to exhibit satisfactory electrochemical performances in supercapacitors and lithium-ion batteries (LIBs). In a three-electrode cell, as-prepared carbon exhibited an excellent capacitance of 263 Fg−1 and an outstanding capacitance retention of 99.67% after 10000 cycles. A soft package symmetric supercapacitor made from the NICP-800 electrode, which used 1 M EMIMBF4/AN as the electrolyte, exhibited a high-energy density of 190 Whkg−1 at a power-density of 1950 Wkg−1 over a voltage range of 4 V. Additionally, the carbon material has a high lithium storage capacity of 886 mAhg−1 and a good rate capability.