that further accentuates the nonuniform deposition, resulting in a branch-like dendritic growth and consumption of the electrolyte. [3][4][5][6] As a result, the use of Li metal anode not only leads to poor performance and low Columbic efficiency (CE), but also short circuits and safety hazards since the dendrites may pierce through the separators.Tremendous efforts have been made to realize uniform metallic Li deposition and construct a stable SEI passive layer to solve these problems, such as the use of a gel polymer/solid-state electrolyte, [7][8][9] the addition of additives to the liquid electrolyte [10][11][12] and the construction of artificial SEI layers. [13][14][15] The current density greatly affects the Li plating behavior according to Sand's time model, [16,17] and transforming the traditional planar electrode into a 3D matrix [18][19][20][21] or nanostructuring the current collectors [22][23][24] can partially solve the above problems because a 3D structure decreases the local current density and regulates the electrical field distribution to allow uniform Li deposition. Considering that a Cu foil is the most commonly used anode current collector, much effort has been devoted to modifying the Cu collector to realize the stable use of Li metal. [25][26][27][28] For example, the 3D Cu current collector with submicron skeleton was prepared by Guo and co-workers to improve the electrochemical deposition behavior of Li. [25] Yun Uncontrollable dendrite growth hinders the direct use of a lithium metal anode in batteries, even though it has the highest energy density of all anode materials. Achieving uniform lithium deposition is the key to solving this problem, but it is hard to be realized on a planar electrode surface. In this study, a thin lithiophilic layer consisting of vertically aligned CuO nanosheets directly grown on a planar Cu current collector is prepared by a simple wet chemical reaction. The lithiophilic nature of the CuO nanosheets reduces the polarization of the electrode, ensuring uniform Li nucleation and continuous smooth Li plating, which is difficult to realize on the normally used lithiophobic Cu current collector surface. The integration of the grown CuO arrays and the Cu current collector guarantees good electron transfer, and moreover, the vertically aligned channels between the CuO nanosheets guarantee fast ion diffusion and reduce the local current density. As a result, a high Columbic efficiency of 94% for 180 cycles at a current density of 1 mA cm −2 and a prolonged lifespan of a symmetrical cell (700 h at 0.5 mA cm −2 ) can be easily achieved, showing a simple but effective way to realize Li metal-based anode stabilization.

lems by the physical confinement with nanostructured carbon materials [4][5][6][7][8] and the chemical adsorption with various noncarbon oxides/sulfides/nitrides. [9][10][11][12][13][14][15][16] However, the weak affinity of carbonbased materials and the limited adsorption capacity of noncarbon materials toward polar LiPSs make these strategies fail to meet the high sulfur loading electrode and the long cycling process. The basic reason should be ascribed to the slow conversion of high concentrated LiPSs, where their accumulation in the electrolyte causes severe shuttling between electrodes.Recently, the catalysis in Li-S batteries has received much attention because the introduction of catalyst accelerates the LiPS conversion and then, fundamentally suppresses their shuttling even with high sulfur loading. [17] To accelerate the conversion of LiPSs, the catalytic materials should not only have strong adsorption ability toward LiPSs, but also the good conductivity and activity for their conversion. Besides, the relatively high surface area for the Li 2 S deposition is also required. Nevertheless, all these characters are hard to be integrated into one material. Our group previously proposed a TiO 2 -TiN heterostructure that combines the advantages of TiO 2 with the strong adsorption ability and TiN with excellent conductivity, and more importantly, forms abundant active interface to realize the smooth trapping-diffusion-conversion of LiPSs. [18] UntilThe lithium-sulfur (Li-S) battery is a next generation high energy density battery, but its practical application is hindered by the poor cycling stability derived from the severe shuttling of lithium polysulfides (LiPSs). Catalysis is a promising way to solve this problem, but the rational design of relevant catalysts is still hard to achieve. This paper reports the WS 2 -WO 3 heterostructures prepared by in situ sulfurization of WO 3 , and by controlling the sulfurization degree, the structure is controlled, which balances the trapping ability (by WO 3 ) and catalytic activity (by WS 2 ) toward LiPSs. As a result, the WS 2 -WO 3 heterostructures effectively accelerate LiPS conversion and improve sulfur utilization. The Li-S battery with 5 wt% WS 2 -WO 3 heterostructures as additives in the cathode shows an excellent rate performance and good cycling stability, revealing a 0.06% capacity decay each cycle over 500 cycles at 0.5 C. By building an interlayer with such heterostructure-added graphenes, the battery with a high sulfur loading of 5 mg cm −2 still shows a high capacity retention of 86.1% after 300 cycles at 0.5 C. This work provides a rational way to prepare the metal oxide-sulfide heterostructures with an optimized structure to enhance the performance of Li-S batteries.

Lithium metal anodes with high energy density are important for further development of next‐generation batteries. However, inhomogeneous Li deposition and dendrite growth hinder their practical utilization. 3D current collectors are widely investigated to suppress dendrite growth, but they usually occupy a large volume and increase the weight of the system, hence decreasing the energy density. Additionally, the nonuniform distribution of Li ions results in low utilization of the porous structure. A lightweight, 3D Cu nanowire current collector with a phosphidation gradient is reported to balance the lithiophilicity with conductivity of the electrode. The phosphide gradient with good lithiophilicity and high ionic conductivity enables dense nucleation of Li and its steady deposition in the porous structure, realizing a high pore utilization. Specifically, the homogenous deposition of Li leads to the formation of an oriented texture on the electrode surface at high capacities. A high mass loading (≈44 wt%) of Li with a capacity of 3 mAh cm−2 and a high average Coulombic efficiency of 97.3% are achieved. A lifespan of 300 h in a symmetrical cell is obtained at 2 mA cm−2, implying great potential to stabilize lithium metal.