Smart Colloid-Assisted Technique Prompts the Evolution of Bamboo Wastes into Nanometal-Inlaid Carbon Microfibers for Sustainable Ni–Fe Batteries

The massive and sustained realization of highly reactive nanometals@carbon scaffold matrix may push forward the further development of next-generation alkaline battery systems. Herein, we put forward a scalable and applicable strategy to convert wasted bamboo products into porous carbon microfibers (CMFs), with Fe or Ni nanoparticles evenly inlaid, using a special and effective “colloid-assisted” approach. Such a smart/economical nanoengineering technique would enable the vast production of uniform “mosaic” hybrid configurations, endowing CMF-based electrodes with desired superiorities like the ease of electrochemical activation, excellent electrical conductivity, and great sustainability/feasibility in real applications. The as-built Fe and Ni nanometals@CMFs can serve as admirable negative and positive electrodes for Ni–Fe cells, respectively, with outstanding electrochemical performances including stable/high specific capacities and good capacity retention over 4000 cycles. The assembled full-cell batteries also demonstrate large specific charge capacity, excellent rate capability, and long-lasting cyclic lifetime as well as high energy/power densities, holding a great promise in near-future low-cost energy-storage usage.