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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]

Highlights: A creative cooperative strategy involving silk fibroin/sericin is proposed for stabilizing high-performance flexible Li–S full batteries with a limited Li excess of 90% by simultaneously inhibiting lithium dendrites, adsorbing liquid polysulfides, and anchoring solid lithium sulfides. Such fabric Li–S full batteries offer high volumetric energy density (457.2 Wh L−1), high-capacity retention (99.8% per cycle), and remarkable bending capability (6000 flexing cycles at a small radius of 5 mm). Lithium–sulfur batteries are highly appealing as high-energy power systems and hold great application prospects for flexible and wearable electronics. However, the easy formation of lithium dendrites, shuttle effect of dissolved polysulfides, random deposition of insulating lithium sulfides, and poor mechanical flexibility of both electrodes seriously restrict the utilization of lithium and stabilities of lithium and sulfur for practical applications. Herein, we present a cooperative strategy employing silk fibroin/sericin to stabilize flexible lithium–sulfur full batteries by simultaneously inhibiting lithium dendrites, adsorbing liquid polysulfides, and anchoring solid lithium sulfides. Benefiting from the abundant nitrogen- and oxygen-containing functional groups, the carbonized fibroin fabric serves as a lithiophilic fabric host for stabilizing the lithium anode, while the carbonized fibroin fabric and the extracted sericin are used as sulfiphilic hosts and adhesive binders, respectively, for stabilizing the sulfur cathode. Consequently, the assembled Li–S full battery provided a high areal capacity (5.6 mAh cm−2), limited lithium excess (90%), a high volumetric energy density (457.2 Wh L−1), high-capacity retention (99.8% per cycle), and remarkable bending capability (6000 flexing cycles at a small radius of 5 mm). [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]