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...

All-solid-state lithium–sulfur batteries (ASLBs) have the potential to achieve high energy density because of sulfur’s high theoretical capacity (1672 mAh g–1) while alleviating persistent polysulfide shuttling inherent to lithium–sulfur batteries based on liquid organic electrolyte. However, the homogenization of sulfur, carbon, and solid electrolyte is a challenge to achieving high-performance cathodes for ASLBs. Herein, we demonstrate a promising sulfur–carbon composite with high sulfur content (71.4–83.3%) prepared using a sulfur vapor deposition (SVD) approach to show enhanced discharge specific capacities, rate performance, and cycling stability, outperforming conventional sulfur liquid deposition (SLD) and sulfur solid deposition (SSD) approaches. A higher discharge specific sulfur capacity of 1792.6 mAh g–1 has been achieved at 0.1C and 60 °C with improvement ascribed to smaller particle size and more homogeneous and deeply confined sulfur in sulfur–carbon composite, in contrast to 1619.2 and 1329.3 mAh g–1 for samples prepared by conventional SLD and SSD approaches, respectively.

Metallic anodes (lithium, sodium, and zinc) are attractive for rechargeable battery technologies but are plagued by an unfavorable metal–electrolyte interface that leads to nonuniform metal deposition and an unstable solid–electrolyte interphase (SEI). Here we report the use of electrochemically labile molecules to regulate the electrochemical interface and guide even lithium deposition and a stable SEI. The molecule, benzenesulfonyl fluoride, was bonded to the surface of a reduced graphene oxide aerogel. During metal deposition, this labile molecule not only generates a metal-coordinating benzenesulfonate anion that guides homogeneous metal deposition but also contributes lithium fluoride to the SEI to improve Li surface passivation. Consequently, high-efficiency lithium deposition with a low nucleation overpotential was achieved at a high current density of 6.0 mA cm−2. A Li|LiCoO2cell had a capacity retention of 85.3% after 400 cycles, and the cell also tolerated low-temperature (−10 °C) operation without additional capacity fading. This strategy was applied to sodium and zinc anodes as well.

The rising energy crisis and environmental concerns caused by fossil fuels have accelerated the deployment of renewable and sustainable energy sources and storage systems. As a result of immense progress in the field, cost-effective, high-performance, and long-life rechargeable batteries are imperative to meet the current and future demands for sustainable energy sources. Currently, lithium-ion batteries are widely used, but limited lithium (Li) resources have caused price spikes, threatening progress toward cleaner energy sources. Therefore, post-Li, batteries that utilize highly abundant materials leading to cost-effective energy storage solutions while offering desirable performance characteristics are urgently needed. Aluminum-ion battery (AIB) is an attractive concept that uses highly abundant aluminum while offering a high theoretical gravimetric and volumetric capacity of 2980 mAh g À 1 and 8046 mAh cm À 3 , respectively. As a result, intensified efforts have been made in recent years to utilize numerous electrolytes, anodes, and cathode materials to improve the electrochemical performance of AIBs, and potentially create high-performance, low-cost, and safe energy storage devices. Herein, recent progress in the electrolyte, anode, and cathode active materials and their utilization in AIBs and their related characteristics are summarized. Finally, the main challenges facing AIBs along with future directions are highlighted.