Stretchable energy-storage devices receive considerable attention due to their promising applications in future wearable technologies. However, they currently suffer from many problems, including low utility of active materials, limited multidirectional stretchability, and poor stability under stretched conditions. In addition, most proposed designs use one or more rigid components that fail to meet the stretchability requirement for the entire device. Here, an all-stretchable-component sodium-ion full battery based on graphene-modified poly(dimethylsiloxane) sponge electrodes and an elastic gel membrane is developed for the first time. The battery exhibits reasonable electrochemical performance and robust mechanical deformability; its electrochemical characteristics can be well-maintained under many different stretched conditions and after hundreds of stretching-release cycles. This novel design integrating all stretchable components provides a pathway toward the next generation of wearable energy devices in modern electronics.

Thermoresponsive smart electrolytes based on Pluronic solution are developed for active control and thermal self-protection of electrochemical energy-storage devices. Mechanistic studies reveal that the highly effective and reversible self-protection behavior is attributed to the sol-gel transition of the Pluronic solution upon temperature change. The transition temperature and the degree of performance suppression can be tuned over a wide range.

Graphene oxide (GO) aerogels, high porosity (>99%) low density (∼3-10 mg cm(-3)) porous materials with GO pore walls, are particularly attractive due to their lightweight, high surface area, and potential use in environmental remediation, superhydrophobic and superoleophilic materials, energy storage, etc. However, pure GO aerogels are generally weak and delicate which complicates their handling and potentially limits their commercial implementation. The focus of this work was to synthesize highly elastic, mechanically stable aerogels that are robust and easy to handle without substantially sacrificing their high porosity or low density. To overcome this challenge, a small amount of readily available and thermally cross-linkable poly(acrylic acid) (PAA) was intermixed with GO to enhance the mechanical integrity of the aerogel without disrupting other desirable characteristic properties. This method is a simple straightforward procedure that does not include multistep or complicated chemical reactions, and it produces aerogels with mass densities of about 4-6 mg cm(-3) and >99.6% porosity that can reversibly support up to 10,000 times their weight with full recovery of their original volume. Finally, pressure sensing capabilities were demonstrated and their oil absorption capacities were measured to be around 120 g oil per g aerogel(-1) which highlights their potential use in practical applications.

The glass transition temperature (T g ), in-plane diffusivity (D), and effective viscosity (η eff ) were measured for the same thin film system of poly(isobutyl methacrylate) supported by silica (PiBMA/SiOx). We found that both the T g and D were independent of the film thickness (h 0 ), but η eff decreased with decreasing h 0 . We envisage the different h 0 dependencies to be caused by T g , D, and η eff being different functions of the local T g 's (T g,i ) or viscosities (η i ), which vary with the film depth. By assuming a three-layer model and that T g (h 0 ) = ⟨T g,i ⟩, D(h 0 ) ∼ k B T/⟨η i ⟩, and η eff (h 0 ) = h 0 3 /3M tot (η i ), where ⟨...⟩ denotes spatial averaging and M tot is the mobility of the films, we were able to account for the experimental data. By extending these ideas to the analogous data of polystyrene supported by silica (PS/SiOx), a resolution was found for the long-standing inconsistency regarding the effects of confinement on the dynamics of polymer films.

A highly effective flame retardant (FR) nanocoating was developed by conducting oxidative polymerization of dopamine monomer within an aqueous liquid crystalline (LC) graphene oxide (GO) scaffold coating. Due to its high water content, the LC scaffold coating approach facilitated fast transport and polymerization of dopamine precursors into polydopamine (PDA) within the water swollen interlayer galleries. Uniform and periodically stacked (14.5 Å d-spacing) PDA/GO nanocoatings could be universally applied on different surfaces, including macroporous flexible polyurethane (PU) foam and flat substrates such as silicon wafers. Remarkably, PDA/GO coated PU foam exhibited highly efficient flame retardant performance reflected by a 65% reduction in peak heat release rate at 5 wt% PDA/GO loading in an 80 nm thick coating. While many physically mixed flame retardants are usually detrimental to the mechanical properties of the foam, the PDA/GO coating did not affect mechanical properties substantially. In addition, the PDA/GO coatings were stable in water due to the intrinsic adhesion capability of PDA and the transformation of GO to the more hydrophobic reduced GO form. Given that PDA is produced from dopamine, a molecule prevalent in nature, these findings suggest that significant opportunities exist for new polymeric FRs derived from other natural catechols.