Gas template assisted activation for N, P dual doped carbon toward high performance zinc-ion hybrid capacitors and zinc-iodine batteries

Porous carbon materials are extensively utilized in the energy storage field due to their affordability, high stability, and excellent electrical conductivity. However, current methods for producing porous carbon typically involve using hard templates or activating with strong acids or bases, resulting in complex procedures and increased environmental impact. In this study, N and P co-doped 3D hierarchical porous foamy carbon (FC) was synthesized using gas template-assisted activation strategies, eliminating the need for strong acids and bases. The unique three-dimensional hierarchical porous structure and multi-element doping of FC-1 resulted in a significant improvement in electrochemical performance. This led to high specific capacitances of 170 mAh g- 1 at 0.1 A g- 1 and 79 mAh g- 1 at 10 A g- 1 , along with a high energy density of 161.5 Wh kg- 1 at a power density of 94.9 W kg- 1 in zinc-ion hybrid capacitors. Additionally, excellent rate performance of 143 mAh g- 1 at 0.1 A g- 1 and 54 mAh g- 1 at 10 A g- 1 , as well as a long cycling life without noticeable capacity decay after 3000 cycles, were observed in zinc-iodine batteries. This research paves the way for designing and preparing porous heteroatom doping carbons for high-energy and safe electrochemical energy storage devices.