A Full‐Device Autonomous Self‐Healing Stretchable Soft Battery from Self‐Bonded Eutectogels

Abstract

tions beyond traditional energy storage, extending the benefits of embodied energy to a wider range of robot designs. [3,4] For example, stretchable batteries can theoretically be used as extensible tendons in walking robots, thereby integrating electrical and elastic energy storage into a single structural element that connects different system components. [4] However, the fabrication of such devices, especially intrinsically stretchable energy storage devices, is still in its infancy. [5][6][7] Previous work has mainly made use of micro/ nano-scale engineering strategies to achieve stretchable electrode/battery configurations, such as buckling, Kirigamipatterning, and rigid-island designs. [6][7][8][9] The complex battery geometries pose difficulties for soft device integration and next-generation on-skin applications. Furthermore, for stretchable energy storage devices, self-healability is especially important for restoring their mechanical integrity and electrochemical functionality when damage occurs during repeated bending, stretching, and electrochemical cycling. [2,3,10] Currently, most of the reported self-healable batteries are not stretchable and rely on self-healable electrodes or electrolytes rather than achieving full-device self-healability. [2,3,10] However, for practical application, the electrode only self-healing capability can only protect the whole battery from physical damages, such as cracks or fractures. The electrolyte only self-healing capability can only protect the whole battery from shorting out. Thus, in order to achieve real self-healing for the entire device, each component of the full battery needs to be self-healable. [3] Despite significant progress in developing self-healing stretchable materials, [11][12][13] skin-like autonomously self-healable and intrinsically stretchable energy storage devices have not been reported yet owing to the highly complex requirements at both materials and device levels. [2,3,10] To realize an autonomously self-healable and intrinsically stretchable battery at full-device level, five autonomous selfhealing and intrinsically stretchable components need to be developed concurrently: anode, cathode, electrolyte, separator, and substrate. [3] However, making each layer intrinsically selfhealable, stretchable, and mechanically robust, while retaining efficient charge transport and robust interfaces between multilayers, is extremely challenging. [11,14] Besides, each layer possesses additional electrical criteria for material and Next-generation energy storage devices should be soft, stretchable, and selfhealable. Previously reported self-healable batteries mostly possess limited stretchability and rely on healable electrodes or electrolytes rather than achieving full-device self-healability. Herein, an all-component self-bonding strategy is reported to obtain an all-eutectogel soft battery (AESB) that simultaneously achieves full-cell autonomous self-healability and omnidirectional intrinsic stretchability (>1000% areal strain) over a broad temperature...

Recent Advance in Stretchable Self‐Powered Piezoelectric Sensors: Trends, Challenges, and Solutions

“…[113,114] Basically, stretchable piezoelectric sensors are based on a sandwiched material system composed of a stretchable responsive layer (piezoelectric materials) and two stretchable conductor layers (as current collectors). In recent year, although tremendous effort in developing stretchable self-healing electrodes, [115][116][117][118][119][120][121] only a limited number of stretchable piezoelectric materials with self-healing ability are explored. [52,73,74,122,123] Therefore, the effort to achieve the self-healing ability of the whole devices remains challenging.…”

Initiatorless Solar Photopolymerization of Versatile and Sustainable Eutectogels as Multi‐Response and Self‐Powered Sensors for Human–Computer Interface

“…[29][30][31] Eutectogels consist of cross-linked polymer networks or lowmolecular-weight gelators aggregated supramolecular network structure with DESs, which have emerged as a new class of soft ionic conductors in the gel family and are still in their infancy in recent years. [32][33][34] In view of the extraordinary elasticity from polymer networks and the inherent high conductivity of DES, eutectogels present great potential in the fields of smart sensing and flexible electronics. In general, in situ radical polymerization of monomers in DES serves as a typical gelation strategy for the preparation of eutectogel, which is trapped in the non-biocompatibility and environmental unfriendliness resulting from the incorporated toxic photoinitiator and crosslinkers in the presence of energy-consuming UV light sources.…”

“…Liu et al reported an all-eutectogel soft battery, the as-prepared soft battery could be easily configured into arbitrary-shaped 3D architectures through self-bonding, self-adhesion, and self-healing of individual components. [33,38] Thus, a substantial need exists for synthesizing multifunctional eutectogels in a facile and green manner.…”

Encapsulating eutectogels for stretchable humidity-resistant strain sensors

“…[4][5][6] Recently, eutectogels synthesized by embedding DESs into solid frameworks, such as polymer matrices, have been gaining more and more attention. 2,7 With the rapid development of stretchable ionotronics, 8 eutectogels open interesting perspectives for applications such as wearable sensors, [9][10][11][12][13][14][15] triboelectric nanogenerators, 16 supercapacitors, 17 soft batteries, 18 and stretchable adhesives, 19,20 although additional efforts are still needed to improve their mechanical and electrical performances. 2,4,21 One of the commonly used DESs is obtained by mixing choline chloride (ChCl) with ethylene glycol (EG) in a molar ratio of 1 : 2.…”