Material Choice and Structure Design of Flexible Battery Electrode

Abstract

With the development of flexible electronics, the demand for flexibility is gradually put forward for its energy supply device, i.e., battery, to fit complex curved surfaces with good fatigue resistance and safety. As an important component of flexible batteries, flexible electrodes play a key role in the energy density, power density, and mechanical flexibility of batteries. Their large‐scale commercial applications depend on the fulfillment of the commercial requirements and the fabrication methods of electrode materials. In this paper, the deformable electrode materials and structural design for flexible batteries are summarized, with the purpose of flexibility. The advantages and disadvantages of the application of various flexible materials (carbon nanotubes, graphene, MXene, carbon fiber/carbon fiber cloth, and conducting polymers) and flexible structures (buckling structure, helical structure, and kirigami structure) in flexible battery electrodes are discussed. In addition, the application scenarios of flexible batteries and the main challenges and future development of flexible electrode fabrication are also discussed, providing general guidance for the research of high‐performance flexible electrodes.

Structural engineering of electrodes for flexible energy storage devices

“…It has been suggested by a series of experimental results, that novel electrodes with modified structures are an effective way to achieve superior mechanical strength and stable electrochemical performances under deformation. 9 A variety of novel structures can be easily produced with desired mechanical properties due to the abundant choice of structures and high degree of freedom in geometry customization using 3D printing technologies. To strike a balance between electrical and mechanical durability of electrodes, different planar and three-dimensional structures including serpentine, 10,11 biomimetic [12][13][14] and auxetic 15,16 structures have been explored as novel electrodes with desired functionalities.…”

Unleashing the Potential of MXene‐Based Flexible Materials for High‐Performance Energy Storage Devices

“…[11][12][13] Thanks to their superior properties such as microscale lateral size, atomic layer thickness, and prominent hydrophilicity, MXenes can be easily assembled into flexible film/paper electrodes by vacuum-assisted filtration or coating techniques. [14][15][16] Additionally, the abundant surface chemistry as well as the high electronegativity imparted by hydrofluoric acidbased etching makes it possible for MXenes to combine with other nanomaterials to prepare high-performance flexible composite electrodes. [17] MXene-based flexible materials illustrate astonishing conductivity and extraordinary flexibility; their high electrical conductivity facilitates fast electron transport, while their unique lamellar structure provides a low diffusion barrier for ion expansion.…”

Locking Water Molecules Loss of PAA Hydrogel for Flexible Zinc‐Air Battery with NaCl Doping

“…[20][21][22] Hydrogels are hydrophilic 3D network structure gels that swell in water and do not dissolve. [23,24] Even after being removed from water, they can still maintain a large amount of water within their structure, putting them in a special state -not quite a complete solid, yet not quite a complete liquid. [25] This state allows hydrogels to maintain a certain shape and volume like a solid, while also allowing solutes to permeate and diffuse through the hydrogel like a liquid.…”