Phosphate Ion Functionalized Co3O4 Ultrathin Nanosheets with Greatly Improved Surface Reactivity for High Performance Pseudocapacitors

A surface-modified Co3O4 ultrathin nanosheet (denoted as PCO) is reported via controllable phosphate ion functionalization for pseudocapacitors. An energy density of 71.6 W h kg−1 (at 1500 W kg−1) is achieved by the PCO-based pseudocapacitor. The unique porous nanosheet morphology, high surface reactivity, and fast electrode kinetics of PCO are found to be responsible for the enhanced pseudocapacitive performance. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.