Laser Hybrid Fabrication Of Micro/Nano Structure For Mn-base Supercapacitor Electrode

With the rapid development of the global economy, environmental degradation and energy shortages are more prominent. The new device with the function of energy storage and conversion become a key factor in solving the energy crisis. The supercapacitor is a new type of energy storage device with high power density, high energy density and long service life. The performance of supercapacitor depends on the electrode material and structure. This research aims to realize the integrated fabrication of electrode materials, structure and function,by laser-chemical hybrid methods through growing the electrode material(manganese carbonate and manganese oxide) with high surface area and porosity directly on current collector surface. The following results are obtained.The fabrication of manganese carbonate microsphere electrode by laser cladding hybrid dealloying method: First, a precusor layer of Cu–Mn alloy was fabricated by laser cladding of Cu and Mn powder on a stainless steel substrate. Next, manganese carbonate microspheres with uniform distribution on the surface of the precusor layer were obtained during dealloying process. The diameter of the microsphere was in a range of 5~10 ?m, and the surface was composed of the edges and corners with a size of about 200 nm. The maximum specific capacitance of the as-fabricated manganese carbonate microsphere electrode was 388 F·g-1. The mechanism of the manganese carbonate microsphere was proposed.The fabrication of micro/nano manganese oxide electrode by femtosecond laser ablation hybrid chemical oxidation method :First, micro/nano structures were fabricated by femtosecond laser ablation on the surface of pure manganese. Next, manganese was converted to manganese oxide by chemical oxidation. The specific capacitance of the conical arrays was 258.5 mF·cm-2. Meanwhile, the conical arrays had a good cycle performance with 15% loss of capacitance after 2000 cycles.The above results proved that three-dimensional micro/nano structures metallurgical bonded with current collector were fabricated by laser-chemical hybrid methods, realizing the electrode materials-structure-function integrated fabrication. This study also provides a new prospect for fabrication of other energy device electrode structures.