The zinc-ion battery (ZIB) is a novel energy storage device, an attractive alternative to the lithium-ion battery. The frequently used aqueous electrolyte suffers from many problems such as zinc dendrites and leakage, which prompts hydrogel electrolytes and solid electrolytes as good replacements. However, hydrogel electrolytes are usually unstable, owing to water volatilization. Herein, a novel solid polymer electrolyte (SPE) utilizing coordination of zinc ions is designed and then introduced into an all-solid ZIB. Benefiting from the unique coordination structure between the polymer and zinc ions, the SPE shows outstanding flexibility, high ion conductivity, and self-healing properties. In addition, the imine bonds in the polymer allow the electrolyte to degrade in acid environments, endowing its recyclability. More importantly, solid-state ZIBs based on the polymer electrolytes exhibit an impressive cycling stability (125% capacity retention after 300 cycles) and a high coulombic efficiency (94% after 300 cycles). The results demonstrate the promising potentials of the developed SPEs that can be used in all-solid ZIBs.

Strong interchain interactions of conjugated polymers usually result in poor miscibility with molecular dopants, limiting the doping efficiency because of uncontrolled phase separation. We have developed a strategy to achieve efficient charge-transport and high doping miscibility in n-doped conjugated polymers. We solve the miscibility issue through disorder side-chains containing dopants better. Systemic structural characterization reveals a farther side-chain branching point will lead to higher disorders, which provides appropriate sites to accommodate extrinsic molecular dopants without harming original chain packings and charge-transport channels. Therefore, better sustainability of solidstate microstructure is obtained, yielding a stable conductivity even when overloading massive dopants. This work highlights the importance of realizing high host-dopant miscibility in molecular doping of conjugated polymers.

A series of block copolymers (BCPs) with a polynorbornene backbone containing short poly(ethylene oxide) (PEO) side chains and rigid side chains were synthesized by tandem ring-opening metathesis polymerization (ROMP). The contents of PEO in the BCPs are regulated by the degrees of polymerization (DPs) of main chains. The crystallization of the PEO side chains is suppressed. Confirmed by small-angle X-ray scattering (SAXS) results, the BCPs doped with lithium salt and ionic liquid self-assemble into lamellar (LAM) or hexagonally packed cylindrical (HEX) nanostructures that remain stable up to 200 °C. The ionic conductivity (σ) values of the complexes with an optimized doping ratio are above the order of 1 × 10 −4 S/cm over the temperature range of −25 to 200 °C, and the highest is 6.41 × 10 −3 S/cm at 200 °C, reaching the top level for PEO-based polymer electrolytes at high temperatures. In addition, the results of shear rheological experiments indicate that the thermally stable electrolyte membranes can maintain the solid state up to 200 °C. These BCP electrolytes with high σ values and excellent thermal stability in a wide temperature range may be applied in high-temperature lithium-ion batteries.