Li metal is considered an ideal anode for the next-generation rechargeable batteries due to the high specific capacity and ultralow redox potential. However, the growth of Li dendrites severely impedes its application. In this study, a structural Li anode is constructed by decorating the copper phosphide nanowires modified copper mesh (PCM) on Li surface. A self-limiting Li deposition with dendrite-free feature is achieved based on the rational surface chemical and structural engineering of the Li anode. On the one hand, the meshed PCM layer as well as its lithiated species performs excellent lithiophilicity and favorable electron/ion conductivity, effectively reducing the Li nucleation barrier and redistributing the electric field and Li+ flux. This promotes a preferential and uniform Li deposition. On the other hand, the suitable combination between PCM and Li not only ensures excellent electrical contact for fast charge transfer, but also establishes a well-balanced structure with abundant active sites and large space for Li nucleation and deposition. Moreover, the meshed surface structure effectively accommodates the volume change of Li during plating/stripping. And the multiplied compressive stress between the PCM and separator greatly suppresses Li growth in vertical direction and promotes a dense Li morphology. Consequently, a self-limiting and highly reversible Li plating/stripping along the horizontal direction is achieved, even at a high areal capacity of 10 mAh cm–2. The Li deposition preferentially occurs on the PCM skeleton and gradually expands horizontally into the meshed space, without obvious formation of Li dendrites. The symmetrical cells show excellent cycling stability for over 1700h with a low overpotential (13.1mV at 1500h) at 1mAcm–2. Furthermore, the cells paired with LiNi0.6Co0.2Mn0.2O2 cathode also show excellent cycling stability for over 450 cycles.

AbstractDue to the limitations of the raw materials and processes involved, polyolefin separators used in commercial lithium‐ion batteries (LIBs) have gradually failed to meet the increasing requirements of high‐end batteries in terms of energy density, power density, and safety. Hence, it is very important to develop next‐generation separators for advanced lithium (Li)‐based rechargeable batteries including LIBs and Li–S batteries. Nonwoven nanofiber membranes fabricated via electrospinning technology are highly attractive candidates for high‐end separators due to their simple processes, low‐cost equipment, controllable microporous structure, wide material applicability, and availability of multiple functions. In this review, the electrospinning technologies for separators are reviewed in terms of devices, process and environment, and polymer solution systems. Furthermore, strategies toward the improvement of electrospun separators in advanced LIBs and Li–S batteries are presented in terms of the compositions and the structure of nanofibers and separators. Finally, the challenges and prospects of electrospun separators in both academia and industry are proposed. We anticipate that these systematic discussions can provide information in terms of commercial applications of electrospun separators and offer new perspectives for the design of functional electrospun separators for advanced Li‐based batteries.

Lithium (Li) metal is a potential anode for high-energy-density batteries because of its low potential and ultrahigh capacity. Nevertheless, the Li dendrites formation, the ununiform Li deposition, and the growth of Li dendrites hamper its application, especially under high deposition capacity/high rate. Here, a spatially controlled Li deposition mode with array-oriented morphology is achieved based on the novel mixed ion/electron-conducting LixCuyPz arrays constructed on Cu foil, which can be facile fabricated via an in-situ transformation of metal phosphide. Theoretic calculations indicate the excellent lithiophilicity and low Li diffusion barrier of the arrays, especially for the Li2CuP phase, which are conducive to ho-mogenizing the Li nucleation/deposition of Li. Moreover, such mixed conducting arrays promote fast Li + diffusion via the continuous Li + pathways as well as modulate the Li + flux/electric field. Furthermore, the arrays with enlarged specific surface area and open spaces reduce the local current density and alle-viate the volume fluctuation of Li. Consequently, a dendrite-free Li anode is obtained under a high rate (20 mA cm-2) or a high deposition capacity (10 mAh cm-2). In addition, even if the negative/positive ratio reduces to only 1.1, the full cells still perform outstanding stability for over 200 cycles. This work empha-sizes the importance of the design of the framework in terms of the intrinsic properties and structure and reveals a pathway for developing Li metal batteries.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.