Nanoporous Conducting Polymer Nanowire Network-Encapsulated MnO2-Based Flexible Supercapacitor with Enhanced Rate Capability and Cycling Stability

Transition-metal-oxide-based electrochemical electrodes usually suffer from poor electron and ion transport, leading to deteriorated rate performance and cycling stability. Herein, we address these issues by developing a facile conducting encapsulation strategy toward a nanoporous PEDOT nanowire/MnO2 nanoparticle/PEDOT nanowire composite electrode. Through encapsulation of the PEDOT nanowire network, the overall electrochemical performance of the resultant composite electrode is substantially enhanced. Specifically, the rate capability and capacitance retention are improved by similar to 48.2 and similar to 33%, respectively, which are 89.8% at 0.8-40 mA/cm2 and 93% after 3000 charge/discharge cycles at 2.0 mA/cm2, respectively. Moreover, the specific capacitance is increased by similar to 6 times of that of the MnO2@PEDOT NW electrode at similar to 200 mA/cm2. We find that a nanoporous conducting nanowire network that encapsulates a MnO2 nanoparticle layer can provide efficient electron and ion transport paths and stabilize the structure of MnO2 from collapse during charge/discharge cycling and mechanical deformation. This strategy can be applied to other pseudocapacitive material-based electrochemical electrodes, such as transition-metal oxides and conducting polymers.

Automated summary

We address the poor electron and ion transport in transition-metal-oxide-based electrochemical electrodes by developing a conducting encapsulation strategy. The performance of the composite electrode is substantially enhanced, improving the rate capability, capacitance retention, and specific capacitance.