Facile in-suit solid-phase synthesis of carbon-coated Ni2P nanospheres decorated on carbon nanotubes with high performance in both supercapacitors and lithium-ion batteries

Low specific surface area and severe agglomeration are the main defects of the energy storage materials (ESMs) fabricated by the solid-phase synthesis (SPS) method. If these defects could be well addressed, the SPS method would be a promising method for the fabrication of high-performance ESMs with the merits of convenience, eco-friendliness, and cost-effectiveness. In this work, an in-suit solid-phase synthesis method is developed for the synthesis of the Ni2P@C/CNT nanocomposite with high performance in both supercapacitor and lithium-ion battery. The carbon-coated Ni2P nanospheres are in-suit synthesized and decorated successfully on the porous high-conductive CNTs framework by the proposed method. An ultra-high specific capacity of 378.5 mAh g−1 at 1 A g−1 and a good rate capacity (189.3 mAh g−1 at 20 A g−1) are presented by the synthesized nanocomposite. Meanwhile, high performance is achieved in both supercapacitor and lithium-ion battery application. Compared to the transition metal phosphide-based nanocomposites reported in literature prepared by the traditional methods, the Ni2P@C/CNT nanocomposite prepared by the proposed in-suit SPS method exhibits very competitive performance in both supercapacitor and lithium-ion battery. The proposed in-suit SPS method is proved to be a promising method for the preparation of high-performance ESMs.