Graphene nanosheet–titanium nitride nanocomposite for high performance electrochemical capacitors without extra conductive agent addition

&nbsp;<br />&nbsp;A graphene nanosheet&ndash;titanium nitride (G&ndash;TiN) nanocomposite has been fabricated through a simple<br /> in situ hydrolysis method combined with ammonia annealing. TiN nanoparticles are homogeneously<br /> anchored on G, which is beneficial for the formation of a porous structure and the enhancement of<br /> electrical conductivity perpendicular to the graphene layers. Such a texture allows for the fast<br /> accessibility of ions and rapid transfer of electrons. In 1MLiPF6&ndash;EC : DEC (vol. 1 : 1) electrolyte, the<br /> specific capacitances of the electrochemical capacitors (ECs) assembled without extra conductive agent<br /> addition, are 560 and 132 F g_1 at current densities of 0.1 and 4 A g_1, respectively. Meanwhile, high<br /> energy densities of 162 and 81 W h kg_1 are obtained at power densities of 150 and 934 W kg<br /> _1,respectively. Even at a higher power density of 4367 W kg _1, a remarkable energy density of 41 W h<br /> Kg _1 is delivered. The unique characteristic of G&ndash;TiN endows the ECs with high energy density and<br /> power density, due to the combination of electric double layer capacitance and lithium ion intercalation<br /> capacitance.