The safe, flexible, and environment-friendly Zn-ion batteries have aroused great interests nowadays. Nevertheless, flagrant Zn dendrite uncontrollably grows in liquid electrolytes due to insufficient surface protection, which severely impedes the future applications of Zn-ion batteries especially at high current densities. Gel electrolytes are emerging to tackle this issue, yet the required high modulus for inhibiting dendrite growth as well as concurrent poor interfacial contact with roughened Zn electrodes are not easily reconcilable to regulate the fragile Zn/Zn²⁺ interface. Here we demonstrate, such a conflict may be defeated by using a mechanoadaptive cellulose nanofibril-based morphing gel electrolyte (MorphGE), which synergizes bulk compliance for optimizing interfacial contact as well as high modulus for suppressing dendrite formation. Moreover, by anchoring desolvated Zn²⁺ on cellulose nanofibrils, the side reactions which induce dendrite formation are also significantly reduced. As a result, the MorphGE-based symmetrical Zn-ion battery demonstrated outstanding stability for more than 100 h at the high current density of 10 mA·cm⁻² and areal capacity of 10 mA·h·cm⁻², and the corresponding Zn-ion battery delivered a prominent specific capacity of 100 mA·h·g⁻¹ for more than 500 cycles at 20 C. The present example of engineering the mechanoadaptivity of gel electrolytes will shed light on a new pathway for designing highly safe and flexible energy storage devices.

Two-dimensional nanosheet membranes with responsive nanochannels are appealing for controlled mass transfer/separation, but limited by everchanging thicknesses arising from unstable interfaces. Herein, an interfacially stable, thermo-responsive nanosheet membrane is assembled from twin-chain stabilized metal-organic framework (MOF) nanosheets, which function via two cyclic amide-bearing polymers, thermo-responsive poly(N-vinyl caprolactam) (PVCL) for adjusting channel size, and non-responsive polyvinylpyrrolidone for supporting constant interlayer distance. Owing to the microporosity of MOF nanosheets and controllable interface wettability, the hybrid membrane demonstrates both superior separation performance and stable thermo-responsiveness. Scattering and correlation spectroscopic analyses further corroborate the respective roles of the two polymers and reveal the microenvironment changes of nanochannels are motivated by the dehydration of PVCL chains.

Using two-dimensional (2D) metal-organic framework (MOF) nanosheets as new building blocks to create more complex architectures at the mesoscopic/macroscopic scale has attracted extensive interest in recent years. Nevertheless, it remains a great challenge to assemble MOF nanosheets into hierarchical hollow structures so far. In this paper, we describe a successful example of hierarchical MOF nanosheet microcapsules, with precisely controlled sizes, produced on large scale within minutes with a continuous droplet microfluidic strategy. Following a reaction/diffusion growth mechanism, the microcapsule shells feature a continuous smooth inner layer and a porous outer layer. Such hierarchical structure enables the encapsulation of magnetite nanoparticles inside and loading of dense gold nanoparticles outside the microcapsules, which exhibit highly efficient heterogeneous catalytic activity and easy recyclability. The present microfluidic assembly method offers a new pathway for preparing hierarchical MOF nanosheet structures, with the potential for extension to the formation of other 2D nanosheets in general.

Silicon with high specific capacity is deemed an ideal anode material for lithium ion batteries, which, however suffers from low cycling life due to its dramatic volume changes. Water-soluble polymer binders recently gain increasing attention by providing an eco-friendly and low-cost way in improving the cycling stability of Si-based anodes. Herein, a novel bioinspired supramolecular mineral hydrogel binder consisting of polyacrylic acid (PAA) physically crosslinked with amorphous calcium carbonate (ACC) nanoparticles is designed for high-performance anodes made from low-cost microsized Si particles. Owing to its organic-inorganic hydrophilic nature, ACC-PAA hybrid binder exhibits the reported highest modulus (~ 22 GPa) for polymer binders in electrolyte, even higher than lithiated Si species (Li1₅Si₄, ~ 12 GPa). Together with its excellent adhesion and electrochemical stability, ACC-PAA binder can effectively suppress the pulverization of Si particles and maintain the mechanical integrity of electrodes during cycling. Therefore, even with a low binder content, the anode still shows an initial discharge capacity of 2, 973 mAh·g⁻¹ and Coulombic efficiency of 81.5%, and retains 75% at a current density of 600 mA·g⁻¹ after 100 cycles. The present organic-inorganic hybrid mineral binder may open a new approach for designing more effective polymer binders for Si-based lithium-ion batteries.