Water-in-Acid Gel Polymer Electrolyte Realized through a Phosphoric Acid-Enriched Polyelectrolyte Matrix toward Solid-State Supercapacitors

Abstract

A new concept of water-in-acid gel polymer electrolytes (GPEs) is introduced. The simple and scalable UV-light-assisted synthesis of a copolymer matrix possessing polyelectrolyte behavior, followed by swelling in minimally diluted H3PO4 (15.1 M/88 wt % aqueous solution), effects formation of a high proton-conducting, self-standing, and mechanically stable polyelectrolyte GPE (PGPE). Retention of high mechanical stability despite the presence of a large amount of liquid species makes it a promising candidate for replacing conventional GPEs. The high proton conductivity (9.8 × 10–2 S cm–1) of the PGPE at an ambient temperature of 303 K is attributed to the high concentration of the conducting species present in the polymer matrix. The PGPE-based polyaniline (PANI) supercapacitor device (PANI-1) with a mass loading of 1 mg cm–2 exhibits a high specific gravimetric capacitance of 385 F g–1 at a current density of 0.25 mA cm–2. At the same current density, the PANI-5 device retains high gravimetric and areal capacitance values of 258 F g–1 and 1288 mF cm–2, respectively. The low equivalent series resistance value of 0.78 Ω (for the PANI-5 device) further proves the excellent electrode–electrolyte interface formed by the water-in-acid GPE. A 100% capacitance retention even after 9000 continuous charge–discharge cycles strongly indicates the feasibility of adopting water-in-acid GPEs in future supercapacitors.

Dendrite Growth Suppression by Zn2+‐Integrated Nafion Ionomer Membranes: Beyond Porous Separators toward Aqueous Zn/V2O5 Batteries with Extended Cycle Life

“…The slightly higher ionic conductivity (2.8 mS cm −1 ) in 3M‐Glass fiber may be due to its better wettability and intrinsic porous nature (Figure S2b, Supporting Information). The activation energy toward ion conduction is calculated from slope of the ln σ versus 1/T plot (Figure b) . The lowest activation energy (0.069 eV) is obtained with the 3M‐Nafion membrane (Figure b) and that with other porous membranes are given in Table S1, Supporting Information.…”

In situpolymerization process: an essential design tool for lithium polymer batteries

“…Nevertheless, the scope of GPEs is broad compared to SPEs, as many other electrochemical devices such as supercapacitors and solar cells prefer GPEs due to the possibility of achieving improved interfacial contact arising from the presence of a certain degree of LE-like character. [251][252][253] The use of cross-linked, interpenetrated, and block copolymer hosts are explored to improve the LE or solvent retention capability in GPEs. However, the non-realistic addition of a liquid component to boost the electrochemical performance will compromise the safety aspects targeted for GPEs due to the decreased mechanical properties (e.g., low tensile strength, shear modulus, Young`s modulus, etc.).…”

Enhanced Solar‐Driven‐Heating and Tough Hydrogel Electrolyte by Photothermal Effect and Hofmeister Effect

“…The gelation kinetics of MoS 2 composite hydrogel was measured by the time sweep measurements through monitoring the evolution of storage modulus G′ and loss modulus G″ as a function of time. As shown in Figure 1b, the equilibrium point for composite hydrogel with 0.4 mg mL −1 MoS 2 occurs after about 600 s under UV irradiation, even faster than some commercial photoinitiators, [ 39,40 ] which indicates the formation of hydrogel and proves the efficient self‐initiation ability of MoS 2 nanosheets. Scanning electron microscope (SEM) was performed to observe the microstructures of hydrogel and verify the Hofmeister effect.…”