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We propose a novel, practical way to prepare nanoporous Sb with different morphologies and Sb particles of varying size through chemical dealloying of Al–Sb alloy ribbon precursors with different compositions, a top-down process.

We have demonstrated a controlled amorphous red phosphorus@Ni–P core@shell nanostructure as an ultralong cycle-life and superior high-rate anode for SIBs through combining electroless deposition with chemical dealloying.

In supercapacitors based on ionic liquid electrolytes, small amounts of absorbed water could potentially reduce the electrochemical window of electrolytes and cause performance degradation. The same would take place if ionic liquids are used as solvents for electrocatalysis involving the dissolved molecular species. In this work, we carry out molecular dynamics simulations, with gold and carbon electrodes in typical ionic liquids, hydrophobic and hydrophilic, to study electrosorption of water. We investigate the effects of hydrophobicity/hydrophilicity of ionic liquids and electrodes on interfacial distribution of ions and electrosorbed water. Results reveal that using hydrophilic ionic liquids would help to keep water molecules away from the negatively charged electrodes, even at large electrode polarizations. This conclusion is supported by electrochemical cyclic voltammetry measurements on gold and carbon electrodes in contact with humid ionic liquids. Thereby, our findings suggest potential mechanisms for protection of electrodes from water electrosorption.

As a potential alternative to lithium-ion batteries, sodium-ion batteries (SIBs) have attracted more and more attention due to the lower cost of sodium than lithium. Red phosphorus (RP) is an especially promising anode for SIBs with the highest theoretical capacity of 2596 mAh g, which faces the challenges of large volume change and low conductivity. Herein, we develop a nanoporous RP on reduced graphene oxide (NPRP@RGO) as a high-performance anode for SIBs through boiling. Its nanoporous structure could accommodate the volume change and minimize the ion diffusion length, and the high electronic conductive network built on RGO sheets facilitates the fast electron and ion transportation. As a result, NPRP@RGO exhibits a superhigh capacity (1249.7 mAh g after 150 cycles at 173.26 mA g), superior rate capability (656.9 mAh g at 3465.28 mA g), and ultralong cycle life at 5.12 A g for RP-based electrodes (775.3 mAh g after 1500 cycles). The successful synthesis of NPRP@RGO marks a significant enhanced performance for RP-based SIB anodes, providing a scalable synthesis route for nanoporous structures.

The lithium storage performance of silicon (Si) can be enhanced by being alloyed with germanium (Ge) because of its good electronic and ionic conductivity. Here, we synthesized a three-dimensional nanoporous (3D-NP) SiGe alloy as a high-performance lithium-ion battery (LIB) anode using a dealloying method with a ternary AlSiGe ribbon serving as the precursor. The morphology and porosity of the as-synthesized SiGe alloy can be controlled effectively by adjusting the sacrificial Al content of the precursor. With an Al content of 80%, the 3D-NP SiGe presents uniformly coral-like structure with continuous ligaments and hierarchical micropores and mesopores, which leads to a high reversible capacity of 1158 mA h g after 150 cycles at a current density of 1000 mA g with excellent rate capacity. The strategy might provide guidelines for nanostructure optimization and mass production of energy storage materials.

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Li deposition in the Li metal batteries principally involves two steps: Li-ion transport in an electrolyte and Li-ion reduction on an electrode. The Li-ion transport, driven by electrodiffusion under an applied electric field, is kinetically much slower than Li-ion reduction on the electrode. [2] The rate difference between them produces a Li-ion concentration polarization near the electrode surface. [3] The concentration polarization is detrimental to a uniform deposition of Li metal and promotes the growth of mossy and dendritic Li due to a limited Li-ion flux focused to the local Li nucleus. [3a,4] The Li-ion transport is thus a critical control step to achieve uniform Li deposition, as also verified by numerous theoretical models where the mobility of Li ions significantly influences the growth of dendrites. [5] Intensive studies have been conducted to suppress the Li dendrite in Li metal batteries with emphases either on tuning interface chemistry of Li electrodes such as optimizing solidelectrolyte interphase (SEI) layers [6] and fabricating artificial protective layers, [1a,7] or on developing new electrode structures such as designing Li metal host [8] and modifying current collectors. [9] Guided by theoretical modeling results of Li dendrite growth, [5] enhancement of Li-ion transport can facilitate achieving dendrite-free deposition of Li metal in Li metal batteries. Recently, our group demonstrated that the electrokinetic phenomena in 3D Li-ion-affinity porous host improves the Li-ion transport and enables dendrite-free deposition of Li metal anodes within the host. [10] Inspired by this finding, we aim to develop a Li-ion transport enhancement layer utilizing electrokinetic phenomena as a protection layer on top of Li metal to achieve 2D dendritefree Li plating/stripping with improved CEs, and thus to enable improved performance of Li metal batteries under lean electrolyte conditions toward achieving high energy density.Conventional protection techniques for Li metal anode rely on either a mechanically robust, dense layer to inhibit Li dendrite growth or a flexible layer to accommodate volume change upon Li metal deposition to achieve dendrite-free Li metal. Different from the protection techniques, here we develop a high-zeta-potential porous film containing nano/submicronsized pores, called a leaky film, to promote electrokinetic phenomena for enhancement of the Li-ion transport (Figure 1a). The leaky film was fabricated on top of Li metal, composed of crosslinked polyethylenimine (PEI)-based polyurea (PEIPU), poly(ethylene oxide) (PEO), and SiO 2 nanoparticles The application of lithium (Li) metal anodes in Li metal batteries has been hindered by growth of Li dendrites, which lead to short cycling life. Here a Li-ion-affinity leaky film as a protection layer is reported to promote a dendritefree Li metal anode. The leaky film induces electrokinetic phenomena to enhance Li-ion transport, leading to a reduced Li-ion concentration polarization and homogeneous Li-ion distribution. As a result...