Electrolyte-Philic Electrode Material with a Functional Polymer Brush.

The electrode materials with advanced surface structure and architecture that effectively wet electrolyte and promote (ad/de)sorption of electrolyte ions. It remains a great challenge to improve the electrode surface-wetting properties when submersed in an electrolyte. Herein, we report a novel "electrolyte-philic electrode material (EEM)" involving interconnected hierarchically porous carbon and a grafted electrolyte-philic polymer chain brush by the surface-initiated electrochemical-mediated atom transfer radical polymerization, named EEM- g-polymer, which possesses higher capacity, almost three times larger than that of the pristine one. The selectivity and responsiveness of the polymer brush can be tailored to different electrolyte environments. The EEM- g-polyvinylpyrrolidone (or EEM- g-sodium polystyrenesulfonate) negative electrodes are combined with Ni(OH)2 positive electrodes for the fabrication of asymmetric supercapacitors. Notably, the device presents a maximum energy density of 27.8 W h/kg (or 27.5 W h/kg) when the power density is 351 W/kg (or 314 W/kg), and the capacitance retention is 70.0% (or 65.0%) of the initial capacitance value after 10 000 cycles.