Covalent Bonding Homo-All-in-One Configuration Enables a Flexible Supercapacitor with Superior Mechanical Durability Exceeding 50 000 Cyclic Deformations

All-in-one configured supercapacitor holds great promisein addressingcyclic deformation-induced relative displacement and delaminationamong electrode/electrolyte/electrode faced by the conventional laminatedsupercapacitor, but its interfacial interactions among heterogeneouselectrode/electrolyte/electrode only depend on weak secondary or physicalbonds, leading to insufficient mechanical durability. Herein, a conceptof covalent bonding homo-all-in-one configuration is proposed to constructstrong covalent bonding interfaces among electrode/electrolyte/electrodecomprising homomatrix polymer PVA through simultaneous chemical cross-linkingof the homomatrixes and interfaces, thereby achieving mechanicallydurable homo-all-in-one supercapacitors (cPMP/cPVA/cPMP HSCs). Basedon the adjustment in cross-linking time, seamlessly integrated interfacesform in the cPMP/cPVA/cPMP HSCs, which achieve high mechanical properties,remarkable interfacial bonding strength, and low interfacial chargetransfer resistance. In sharp contrast to conventional laminated supercapacitors,the cPMP/cPVA/cPMP HSCs deliver superior areal capacitance of 268.8mF cm(-2) at 5 mV s(-1) and unexpectedcyclic stability with capacitance retention of 104% after 20 000charge-discharge cycles. It is highlighted that the cPMP/cPVA/cPMPHSCs reach an unprecedented level of mechanical durability with capacitanceretention of 103% and 101% exceeding 50 000 bending and twistingcycles, respectively. Furthermore, the cPMP/cPVA/cPMP HSCs are demonstratedto light up a red LED bulb under flat, bending, twisting, and evenfolding conditions. Those findings are intended to lead to an advanceddesign trend for the development of covalent bonding homo-all-in-oneconfigured supercapacitors toward flexible and wearable electronicapplications.