Intrinsically Stretchable Supercapacitors Composed of Polypyrrole Electrodes and Highly Stretchable Gel Electrolyte

Abstract

There has been an emerging interest in stretchable power sources compatible with flexible/wearable electronics. Such power sources must be able to withstand large mechanical strains and still maintain function. Here we report a highly stretchable H3PO4-poly(vinyl alcohol) (PVA) polymer electrolyte obtained by optimizing the polymer molecular weight and its weight ratio to H3PO4 in terms of conductivity and mechanical properties. The electrolyte demonstrates a high conductivity of 3.4 x 10-3 S cm-1, and a high fracture strain at 410% elongation. It is mechanically robust with a tensile strength of 2 MPa and a Young's modulus of 1 MPa, and displays a small plastic deformation (5%) after 1000 stretching cycles at 100% strain. A stretchable supercapacitor device has been developed based on buckled polypyrrole electrodes and the polymer electrolyte. The device shows only a small capacitance loss of 5.6% at 30% strain, and can retain 81% of the initial capacitance after 1000 cycles of such stretching. ABSTRACT: There has been an emerging interest in stretchable power sources compatible with flexible/wearable electronics. Such power sources must be able to withstand large mechanical strains and still maintain function. Here we report a highly stretchable H 3 PO 4 -poly(vinyl alcohol) (PVA) polymer electrolyte obtained by optimizing the polymer molecular weight and its weight ratio to H 3 PO 4 in terms of conductivity and mechanical properties. The electrolyte demonstrates a high conductivity of 3.4×10 -3 S cm -1 , and a high fracture strain at 410% elongation. It is mechanically robust with a tensile strength of 2 MPa and a Young's modulus of 1 MPa, and displays a small plastic deformation (5%) after 1000 stretching cycles at 100% strain. A stretchable supercapacitor device has been developed based on buckled polypyrrole electrodes and the polymer electrolyte. The device shows only a small capacitance loss of 5.6% at 30%strain, and can retain 81% of the initial capacitance after 1000 cycles of such stretching.2

Biocompatible Ionic Liquid–Biopolymer Electrolyte-Enabled Thin and Compact Magnesium–Air Batteries

“…32 Briefly, the electrodeposition was conducted at a constant current of 0.5 mA cm -2 for 30 min in a solution containing 0.1 M pyrrole monomer and 0.1 M p-toluene sulfonic acid sodium salt. The surface morphologies of PPy-pTS were investigated by FE-SEM (JEOL JSM-7500FA).…”

Flexible free-standing graphene paper with interconnected porous structure for energy storage

“…To fabricate flexible all-solid-state supercapacitor, the graphene paper was pasted onto gold-coated PET substrate using silver paste. A gel electrolyte, PVA/ H 2 SO 4 (1:1, weight ratio) was prepared following the procedure described in our previous report, 29 and dropped onto the graphene electrode and dried at room temperature for 12 h. Two such electrodes were held together using fresh polymer electrode as glue ( Figure 1). Figure 1 Schematic procedure to fabricate flexible all solid-state supercapacitors.…”

Gel Polymer Electrolytes for Electrochemical Energy Storage

“…[10][11][12][13] As a consequence, GPEs have become one of the most desirable alternatives among various electrolytes for the electrochemical energy storage devices, and significant progress has been made in lithium-ion batteries (LIBs), supercapacitors (SCs), lithium-oxygen (Li-O 2 ) batteries as well as the other kinds of electrochemical energy storage devices, such as sodium-ion batteries, lithium-sulfur batteries, fuel cells, and zinc-air batteries. [14][15][16] In order to meet the requirements of wearable devices for flexibility and deformability, more special GPEs with tough, [17] stretchable, [18] and compressible [19] functionalities have been also developed.Typically, a polymeric framework is adopted in GPEs as host material, providing high mechanical integrity. Several criteria for a good polymer host lie in: [20][21][22] (i) fast segmental motion of polymer chain; (ii) special groups promoting the dissolution of salts; (iii) low glass transition temperature (T g ); (iv) high molecular weight; (v) wide electrochemical window; (vi) high degradation temperature.…”

“…[10][11][12][13] As a consequence, GPEs have become one of the most desirable alternatives among various electrolytes for the electrochemical energy storage devices, and significant progress has been made in lithium-ion batteries (LIBs), supercapacitors (SCs), lithium-oxygen (Li-O 2 ) batteries as well as the other kinds of electrochemical energy storage devices, such as sodium-ion batteries, lithium-sulfur batteries, fuel cells, and zinc-air batteries. [14][15][16] In order to meet the requirements of wearable devices for flexibility and deformability, more special GPEs with tough, [17] stretchable, [18] and compressible [19] functionalities have been also developed.…”