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Flexible all solid-state batteries that combine polymer electrolytes and lithium metal are required for powering wearable electronic devices as they embody high flexibility, safety and energy density. However, it has been challenging to develop room temperature flexible solid-state batteries because of the low ionic conductivities of polymeric ion conductors. Here, we report a highly conductive polymer electrolyte based on lowly viscous polyethylene oxide ion conductors confined inside an ultrastrong and ultrathin nanofibrous polyethylene membrane. The newly developed solid polymer electrolyte exhibits high room temperature charge transfer conductance (0.07 S) and excellent compatibility with Li metal (cycling time > 3500 hours at 0.1 mA cm−2) at 30 °C. Large-scale molecular dynamics simulations show that the high ionic conductivity is because of the enhanced segmental mobility of confined PEO inside the nanomembrane and the strong charge–dipole interactions between the PEO and lithium ions. This work provides a viable solution toward room temperature workable solid-state batteries that meet the requirements for wearable electronic devices. [ABSTRACT FROM AUTHOR]

The emerging micromotors have shown great potential as delivery vehicles due to their promising transport capacity and ability to dynamically respond to the environment. We report here a multi-stage hydrogel rocket with precise control of the step-by-step detachment of the hydrogel stage and tunable cargo release ability. The hydrogel rocket, constructed from driving hydrogel blocks alternating with sacrificial hydrogel blocks, could propel itself fast driven by the Marangoni effect and drops off self-propelled small rockets by thermal/light stimulation. Furthermore, the tunable release of the payload in the hydrogel rocket was demonstrated. This multi-stage hydrogel rocket may provide new insight into the design of micromotors with on-demand cargo transport and delivery capabilities. [ABSTRACT FROM AUTHOR]

The development of autonomous micro/nano-scale objects has drawn considerable attention in recent years. Here we describe a two-stage hydrogel rocket that displays promising autonomous motion with a propelling speed of over 20 mm s−1 and more remarkably achieves a long transportation period and the release of self-propelled Janus micromotors. Such an attractive hydrogel rocket holds great potential for the protected delivery of active cargoes and future diverse applications of nano/micro machines. [ABSTRACT FROM AUTHOR]

Highly adhesive binders are developed to prolong the cycle life of silicon anodes and accelerate their practical application. A series of poly(N-methacryloyl-3,4-dihydroxy- l -phenylalanine) (PMDOPA) binders, containing ultra-high content of catechol groups, are synthesized through radical polymerization and applied to silicon anodes. The ultra-high content of catechol groups endows the PMDOPA binder superior adhesive strength compared to the carboxyl groups of the polyacrylic acid (PAA) binder. As the molecular weight increases, the flexibility, solvent resistance and adhesive strength of the PMDOPA binders are all enhanced, which effectively alleviates the electrode pulverization during long-term cycling and prolongs the cycle life of batteries. Especially, the PMDOPA-20 binder, which possesses the highest molecular weight of 208 kDa among all the PMDOPA samples, exhibits the longest cycle life of 665 cycles at the current density of 840 mA g−1, even though its molecular weight is lower than PAA. This work demonstrates that both the functional adhesive group and molecular weight are crucial for binder performance, which provides a valuable reference for the future development of high-performance binders. Image 1 • A series of binders containing ultra-high content of catechol groups are synthesized. • Silicon anode performance is improved as the binder molecular weight increases. • The silicon electrodes with catechol-based binders exhibit long cycle lives. • Both functional group and molecular weight are crucial for binder performance. [ABSTRACT FROM AUTHOR]