Low-Temperature-Resistant Flexible Solid Supercapacitors Based on Organohydrogel Electrolytes and Microvoid-Incorporated Reduced Graphene Oxide Electrodes

Abstract

Maintaining enough flexibility and satisfied electrochemical performance simultaneously at subzero temperatures is still challengeable for flexible solid supercapacitors. In the present work, by adopting an organohydrogel electrolyte and reduced graphene oxide (rGO) films with microvoids serving as electrodes, a supercapacitor, which could be steadily operated down to −60 °C, has been obtained and has shown excellent low-temperature tolerance. The organohydrogel electrolyte consists of LiCl in glycerol/water solution containing polyvinyl alcohol, exhibiting excellent flexibility at −60 °C. Due to the introduction of micropores between rGO sheets, the porous membrane can be folded even in liquid nitrogen. Combining the rGO electrodes with the organohydrogel electrolyte, the maximum voltage of the present supercapacitor could be extended to 2.0 V, and a capacitance of 7.73 F·g–1 at −60 °C could be achieved. After 5000 charge/discharge cycles at −20 °C, the capacitance retention rate is 87.5%. The excellent flexibility and low-temperature resistance of the current supercapacitor pave a novel way for developing compression-resistant electronic samples compatible with a low-temperature environment.

A flexible solid-state supercapacitor with extreme low-temperature tolerance based on an ion conducting ice gel electrolyte

“…GO colloid was prepared from purified natural graphite according to a modified Hummers method. 25,26 Briefly, graphite powder (3.0 g) and KMnO 4 (18.0 g) were gradually added to concentrated H 2 SO 4 (360 mL) and H 3 PO 4 (40 mL) with good stirring in an ice bath at 0 °C. Next, the mixture was heated to 50 °C and maintained for 8 h, then cooled to room temperature.…”

“…GO colloid was prepared from puried natural graphite according to a modied Hummers method. 25,26 Briey, graphite powder (3.0 g) and KMnO 4 (18.0 g) were gradually added to concentrated H 2 SO 4 (360 mL) and H 3 PO 4 (40 mL) with good stirring in an ice bath at 0 C. Next, the mixture was heated to 50 C and maintained for 8 h, then cooled to room temperature. Thereaer cooled deionized water (500 mL) was added to the mixture in an ice bath, and aer that H 2 O 2 (30 wt%, 80 mL) was added until the color of the mixture turned from brown to brilliant yellow.…”

Constructing Flexible All‐Solid‐State Supercapacitors from 3D Nanosheets Active Bricks via 3D Manufacturing Technology: A Perspective Review

“…[11,12] On the other hand, the development of hydrogel-based electrolytes (high flexibility and high security) and non-hydrogel-based electrolytes (high voltage window and low temperature resistance) with multiple characteristics (stretchable, self-healing, and compressible) is also critical for flexible all-solid-state supercapacitors. [13][14][15] Ultrathin 2D nanomaterials (including carbon-based and metallic nanosheet materials) with high specific surface area play an important role in improving the capacitance characteristics of supercapacitors. [16][17][18] However, during the electrode preparation process, the irreversible stacking of 2D nanosheets caused by van der Waals force, greatly reduces the available surface area and hinders the transport of electrolyte ions, which affects the specific capacitance and rate performance of electrode materials.…”

Compressible piezoresistive pressure sensor based on Ag nanowires wrapped conductive carbonized melamine foam

“…Due to the advancement of Artificial Intelligence technology and smart electronics, wearable sensing technology has been developed rapidly and widely used in daily life [1][2][3][4][5]. As one of the important components of wearable sensing technology, the flexible pressure sensor has been applied to monitor human movement and health [6].…”