Doping Ni: an effective strategy enhancing electrochemical performance of MnCO.sub.3 electrode materials for supercapacitors

Ni-doped MnCO.sub.3 microspheres were successfully synthesized via a one-step mixed solvent-thermal method. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and N.sub.2 adsorption-desorption measurements. The fabricated Ni-doped MnCO.sub.3 microspheres exhibited a higher specific capacity (538 F g.sup.-1 at a current density of 1 A g.sup.-1) than pure MnCO.sub.3 (287 F g.sup.-1). In addition, 85.8 % of initial capacity was retained after 3000 cycles at a current density of 5 A g.sup.-1, demonstrating a good cycling performance. These results suggested that Ni-doped MnCO.sub.3 microspheres material was a promising candidate for high energy storage applications. Hence doping heterogeneous element with good electrical conductivity was an effective approach to improve the electrochemical performance of the electrode materials.