Aqueous zinc-ion batteries are regarded as the promising candidates for large-scale energy storage systems owing to low cost and high safety; however, their applications are restricted by their poor low-temperature performance. Herein, a low-temperature electrolyte for low-temperature aqueous zinc-ion batteries is designed by introducing low-polarity diglyme into an aqueous solution of Zn(ClO₄)₂. The diglyme disrupts the hydrogen-bonding network of water and lowers the freezing point of the electrolyte to −105 °C. The designed electrolyte achieves ionic conductivity up to 16.18 mS cm⁻¹ at −45 °C. The diglyme and ClO₄⁻ reconfigure the solvated structure of Zn²⁺, which is more favorable for the desolvation of Zn²⁺ at low temperatures. In addition, the diglyme effectively suppresses the dendrites, hydrogen evolution reaction, and by-products of the zinc anode, improving the cycle stability of the battery. At −20 °C, a Zn||Zn symmetrical cell is cycled for 5200 h at 1 mA cm⁻² and 1 mA h cm⁻², and a Zn||polyaniline battery achieves an ultra-long cycle life of 10 000 times. This study sheds light on the future design of electrolytes with high ionic conductivity and easy desolvation at low temperatures for rechargeable batteries.

Osteoimmunomodulation was identified as a new and important strategy to enhance osteogenic differentiation together with other osteogenic approaches. However, approaches regulating osteogenic differentiation and macrophage polarization to remodel an osteoinductive microenvironment are separate and complicated. Therefore, the design and synthesis of one biomaterial that couples the osteogenic performance and immunomodulatory ability is a major challenge for efficient bone repair. In this study, self-assembled iron–catechin nanoparticles (Fe–cat NPs) were designed based on the coordinated reaction between iron ions and catechin and synthesized via a facile one-pot strategy. Interestingly, Fe–cat NPs show intracellular pH-responsive disassembly and release catechin molecules under the low pH of lysosomes after endocytosis. This strategy delivers catechin intracellularly and then enhances the osteogenic differentiation while inhibits the adipogenic differentiation of human adipose-derived stem cells (hADSCs). More importantly, Fe–cat NPs remodel the osteogenic immune microenvironment by resisting inflammation and promoting M2 polarization of macrophages. As a promising metal–organic nanodrug, the intracellular pH-responsive Fe–cat NPs significantly enhance the therapeutic effect of bone regneration by orchestrating osteogenic differentiation and immunomodulation, which may have great potential in bone tissue engineering.