Li-metal batteries (LiMBs) are experiencing a renaissance; however, achieving scalable production of dendrite-free Li anodes for practical application is still a formidable challenge. Herein, a facile and universal method is developed to directly reduce graphene oxide (GO) using alkali metals (e.g., Li, Na, and K) in moderate conditions. Based on this innovation, a spontaneously reduced graphene coating can be designed and modulated on a Li surface (SR-G-Li). The symmetrical SR-G-Li|SR-G-Li cell can run up to 1000 cycles at a high practical current density of 5 mA cm without a short circuit, demonstrating one of the longest lifespans reported with LiPF -based carbonate electrolytes. More significantly, a practically scalable paradigm is established to fabricate dendrite-free Li anodes by spraying a GO layer on the Li anode surface for large-scale production of LiFePO /Li pouch cells, reflected by the continuous manufacturing of the SR-G-Li anodes based on the roll-to-roll technology. The strategy provides new commercial opportunities to both LiMBs and graphene.

Lithium–sulfur (Li–S) batteries are strong contenders among lithium batteries due to superior capacity and energy density, but the polysulfide shuttling effect limits the cycle life and reduces energy efficiency due to a voltage gap between charge and discharge. Here, we demonstrate that graphene foam impregnated with single-atom catalysts (SACs) can be coated on a commercial polypropylene separator to catalyze polysulfide conversion, leading to a reduced voltage gap and a much improved cycle life. Also, among Fe/Co/Ni SACs, Fe SACs may be a better option to be used in Li–S systems. By deploying SACs in the battery separator, cycling stability improves hugely, especially considering relatively high sulfur loading and ultralow SAC contents. Even at a metal loading of ∼2 μg in the whole cell, an Fe SAC-modified separator delivers superior Li–S battery performance even at high sulfur loading (891.6 mAh g–1, 83.7% retention after 750 cycles at 0.5C). Our work further enriches and expands the application of SACs catalyzing polysulfide blocking and conversion and improving round trip efficiencies in batteries, without side effects such as electrolyte and electrode decomposition.

Rechargeable lithium (Li) metal batteries hold great promise for revolutionizing current energy‐storage technologies. However, the uncontrollable growth of lithium dendrites impedes the service of Li anodes in high energy and safety batteries. There are numerous studies on Li anodes, yet little attention has been paid to the intrinsic electrocrystallization characteristics of Li metal and their underlying mechanisms. Herein, a guided growth of planar Li layers, instead of random Li dendrites, is achieved on self‐assembled reduced graphene oxide (rGO). In situ optical observation is performed to monitor the morphology evolution of such a planar Li layer. Moreover, the underlying mechanism during electrodeposition/stripping is revealed using ab initio molecular dynamics simulations. The combined experiment and simulation results show that when Li atoms are deposited on rGO, each layer of Li atoms grows along (110) crystallographic plane of the Li crystals because of the fine in‐plane lattice matching between Li and the rGO substrate, resulting in planar Li deposition. With this specific topographic characteristic, a highly flexible lithium–sulfur (Li–S) full cell with rGO‐guided planar Li layers as the anode exhibits stable cycling performance and high specific energy and power densities. This work enriches the fundamental understanding of Li electrocrystallization without dendrites and provides guidance for practical applications.

In both artificial electronic and ionic skins, the distinction of multi-stimuli response in a single sensing unit is challenging, due to unavoidable mutual signal interference. Here, a zwitterionic skin sensor system that can continuously monitor and differentiate three-stimuli-responsive information in real-time is designed. This sandwich-structured sensor system is based on a zwitterionic thermo-glucose-sensitive skin-like hydrogel at its upper and lower layers with a middle isolation elastomer layer, enabling monitoring and distinction of temperature, mechanical and glucose information without signal interference: 1) the capacitance of the upper/lower layers as glucosetemperature-insensitive is variable to measure strain; 2) the resistance of the upper hydrogel as glucose-insensitive is variable to measure strain and temperature; and 3) the resistance of the lower hydrogel can detect three indicators. Based on the skin sensor system, a smart wound dressing is developed to pro-heal chronic diabetic wounds and enable continuous realtime monitoring of three indicators-infection, swelling, and blood glucose. This work provides a new method of real-time monitoring and the distinction of multi-stimuli response in a wearable device.