Material Choice and Structure Design of Flexible Battery Electrode

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.

Investigation of Ice-Templated Porous Electrodes for Application in Organic Batteries

Application and investigation of porous composite electrodes for organic batteries fabricated by an ice-templating method are reported for the first time. The possibility to produce polymer composite electrodes with highly aligned, parallel pores is demonstrated and electrochemical investigations are presented to examine their suitability for application in organic batteries. The performance of such ice-templated porous electrodes is experimentally compared with planar electrodes of similar composition against zinc and lithium counter electrodes, respectively. Fundamental properties limiting the performance of ice-templated porous electrodes are discussed and further means to overcome those limitations are proposed.

Surface Modified Nanocellulose Fibers Yield Conducting Polymer-Based Flexible Supercapacitors with Enhanced Capacitances

We demonstrate that surface modified nanocellulose fibers (NCFs) can be used as substrates to synthesize supercapacitor electrodes with the highest full electrode-normalized gravimetric (127 F g(-1)) and volumetric (122 F cm(-3)) capacitances at high current densities (300 mA cm(-2) ≈ 33 A g(-1)) until date reported for conducting polymer-based electrodes with active mass loadings as high as 9 mg cm(-2). By introducing quaternary amine groups on the surface of NCFs prior to polypyrrole (PPy) polymerization, the macropore volume of the formed PPy-NCF composites can be minimized while maintaining the volume of the micro- and mesopores at the same level as when unmodified or carboxylate groups functionalized NCFs are employed as polymerization substrates. Symmetric, aqueous electrolyte-based, devices comprising these porosity-optimized electrodes exhibit device-specific volumetric energy and power densities of 3.1 mWh cm(-3) and 3 W cm(-3) respectively; which are among the highest values reported for conducting polymer electrodes in aqueous electrolytes. The functionality of the devices is verified by powering a red light-emitting diode with the device in different mechanically challenging states.

Is there a future for electrochemically assisted hemodialysis? Focus on the application of polypyrrole–nanocellulose composites

This work summarizes the various aspects of using electrochemically assisted solute removal techniques in hemodialysis with a focus on blood electrodialysis and electrochemically controlled uremic retention solute removal using polypyrrole. In particular, the feasibility of using highly porous conductive polypyrrole–Cladophora cellulose membranes for hemodialysis are overviewed as a part of our dedicated research efforts during the past 4 years. The potential benefits and the current limitations associated with using the electrochemically controlled uremic retention solute removal techniques are discussed in detail.