A Universal Converse Voltage Process for Triggering Transition Metal Hybrids In Situ Phase Restruction toward...

Defect engineering holds great promise for precise configuration of electrode materials for dramatically enhanced performance in the field of energy storage, but the high energy/large time cost and lack of control involved in this process represent a serious limit to its use. In response, a low-energy-cost and ultrafast universal converse voltage process is developed to effectively activate the capacitive performance of transition metal compounds integrated on carbon fiber paper, including Co-, Ni-, Mn-, Fe-, and Cr-based hybrids. As a representative example, this process triggers a phase conversion from cobalt hydroxide to electric-field-activated CoOOH (EA-CoOOH), leading to the formation of molecular structure with abundant defects, lattice disorders, and connecting holes, responsible for an enhanced performance within 10 min at room temperature. Moreover, the retained Co²⁺ in EA-CoOOH results in increased activity, confirmed by density functional theory calculations. Consequently, these EA-CoOOH hybrids deliver a capacitance value of 832 F g^-1 at a current density of 1 A g^-1 and exhibit a retention rate up to 78% (649 F g^-1 ) at a super-large current density of 200 A g^-1 . This technology paves a way for ultrafast configuration/modulation of defects on advanced materials toward application in the fields of energy and catalysis.