A study on the preparation of polycation gel polymer electrolyte for supercapacitors.

The polycation gel polymer electrolyte (PGPE) is a promising electrolyte material for supercapacitors due to its high ionic conductivity and great flexibility. Herein, we report a novel flexible PGPE film, which is prepared by thermal copolymerization. The superiority of PGPE is attributed to the existence of charged groups in the polymer skeleton. Consequently, the crystallinity of the polymer is effectively reduced, and the migration of the lithium ion is evidently promoted. Moreover, the liquid retention capacity of the film is improved, which enhances its ionic conductivity as well. The reported PGPE exhibits a high ionic conductivity of 57.6 mS cm-1 at 25 °C and a potential window of 0-1.2 V. The symmetrical PGPE supercapacitor (AC/AC) shows 95.21% mass-specific capacitance retention after 5000 cycles at 2 A g-1 with a maximum energy density of 12.8 W h kg-1 and a maximum power density of 5.475 kW kg-1. This study confirms the exciting potential of PGPE for high performance supercapacitors.

A flexible polyelectrolyte-based gel polymer electrolyte for high-performance all-solid-state supercapacitor application.

A simple polymerization process assisted with UV light for preparing a novel flexible polyelectrolyte-based gel polymer electrolyte (PGPE) is reported. Due to the existence of charged groups in the polyelectrolyte matrix, the PGPE exhibits favorable mechanical strength and excellent ionic conductivity (66.8 mS cm-1 at 25 °C). In addition, the all-solid-state supercapacitor fabricated with a PGPE membrane and activated carbon electrodes shows outstanding electrochemical performance. The specific capacitance of the PGPE supercapacitor is 64.92 F g-1 at 1 A g-1, and the device shows a maximum energy density of 13.26 W h kg-1 and a maximum power density of 2.26 kW kg-1. After 10 000 cycles at a current density of 2 A g-1, the all-solid-state supercapacitor with PGPE reveals a capacitance retention of 94.63%. Furthermore, the specific capacitance and charge-discharge behaviors of the flexible PGPE device hardly change with the bending states.

High-Performance Ionic Liquid-Based Gel Polymer Electrolyte Incorporating Anion-Trapping Boron Sites for All-Solid-State Supercapacitor Application.

A high-performance boron-containing gel polymer electrolyte (GPE) with semi-interpenetrating polymer network structure was successfully prepared by a rapid and easy one-step polymerization process assisted with UV light, exploiting poly(ethylene oxide) as a polymer host, the novel borate ester monomer as the cross-linker, and LiClO4 and EMIMBF4 both as the plasticizer and electrolytic salt, respectively. Owing to the incorporation of anion-trapping boron sites, the ionic conductivity of the as-prepared GPE at room temperature can be up to 5.13 mS cm-1. In addition, the boron-containing GPE (B-GPE) exhibits favorable mechanical strength, excellent thermal stability, and extremely low flammability. Moreover, the all-solid-state symmetric supercapacitor using B-GPE as the electrolyte and reduced graphene oxide as the electrode was fabricated and exhibited a broad potential window (3.2 V). The all-solid-state symmetric supercapacitor based on B-GPE can still reach a high energy density of 27.62 W h kg-1 with a power density of 6.91 kW kg-1 at a high current density of 5 A g-1. After 5000 cycles at a current density of 1 A g-1, the all-solid-state supercapacitor with B-GPE displays a decent capacitance retention of 91.2%.