In situ growth of Cu2+1O/Cu2(CO3)(OH)2/Co(OH)2 with multi-dimensional hybrid structure for high performance flexible supercapacitors

In situ growth of Cu 2+1 O/Cu 2 (CO 3 )(OH) 2 /Co(OH) 2 on carbon cloth (CC) is achieved via a facile wet chemical oxidation strategy combined with hydrothermal method , and the self-supported Cu 2+1 O/Cu 2 (CO 3 )(OH) 2 /Co(OH) 2 displays a unique multi-dimensional hybrid structure. Cu 2+1 O (CuO with excess metal defects) electroless plated on the surface of CC can not only retain the nanostructures of Cu 2 (CO 3 )(OH) 2 and Co(OH) 2 , but also act as the buffer layer to ease volumetric expansion of the materials during the repeated charge/discharge process. When the CC@Cu 2+1 O/Cu 2 (CO 3 )(OH) 2 /Co(OH) 2 is used in flexible supercapacitors , it exhibits significantly enhanced areal specific capacitance (624.5 mF cm 2 at 0.5 mA cm 2 ), rate capability (86.6 %), cyclic stability (100.3 % retention after 1500 cycles) and coulombic efficiency (99.3 % retention after 1500 cycles) due to the synergistic effect of Cu 2+1 O buffer layer, two-dimensional (2D) Co(OH) 2 nanosheets and three-dimensional (3D) Cu 2 (CO 3 )(OH) 2 nanoblocks.