Lithium (Li) metal is the most promising electrode for next-generation rechargeable batteries. However, the challenges induced by Li dendrites on a working Li metal anode hinder the practical applications of Li metal batteries. Herein, nitrogen (N) doped graphene was adopted as the Li plating matrix to regulate Li metal nucleation and suppress dendrite growth. The N-containing functional groups, such as pyridinic and pyrrolic nitrogen in the N-doped graphene, are lithiophilic, which guide the metallic Li nucleation causing the metal to distribute uniformly on the anode surface. As a result, the N-doped graphene modified Li metal anode exhibits a dendrite-free morphology during repeated Li plating and demonstrates a high Coulombic efficiency of 98 % for near 200 cycles.

Lithium (Li) metal is among the most promising anode materials for nextgeneration high-energy-density batteries. However, both dendrite growth and unstable solid electrolyte interphases have hindered its practical applications. Herein, we propose a coralloid carbon fiber-based composite lithium anode, which is an initially Li-containing structured anode. Such electrode design renders dendrite-free morphology during repeated stripping/plating cycles and extraordinary electrochemical performance in Li-LiFePO 4 and Li-sulfur cells.

remarkable evolutions with continuous performance improvements, [4] after three decades of continuous research and development, the typical LIBs employ graphite (theoretical capacity of 372 mAh g −1) as the anode. [5] The energy density of LIB progressively approaches its theoretical limit. Therefore, exploring the next generation anode materials, which can break the ceiling of theoretical capacity of LIBs, is essential for the emerging applications to achieve wireless and green world. [6] Li metal is highly recognized as the very promising alternative anode material due to its low electrochemical potential of −3.04 V versus the standard hydrogen electrode and ultrahigh theoretical capacity of 3860 mAh g −1 , [7] which is almost 10 times of commercial graphite anode. Nevertheless, the disordered Li dendrite deposition during charge/discharge process motivates the dramatical fluctuation of the surface of Li anode, thus resulting in the break/ repair of the solid-electrolyte interphase (SEI) with severe phase migrations, electrolyte consumptions and thermal accumulations. [8] The unexpected microstructural Li dendrite can easily loss the electric connection with the bulk Li or current collector and subsequently form "dead Li," causing severe capacity loss. [9] Moreover, Li dendrite deposition not only aggravates battery performance with low Coulombic efficiency (CE) and rapid capacity decay, [10] but also engenders thermal runaway and even serious safety hazards caused by the internal shorting. [11] Therefore, preventing the lithium dendrite growth plays the key role to accomplish the next-generation highenergy-density and safe Li metal batteries (LMBs). [12] How to suppress the Li dendrite growth raises an inescapable question: why Li tends to deposit dendritic morphology? The formation of Li dendrite undergoes two process including Li nucleation and Li growth. [13] The growth process immediately follows nucleation and develops on the surface of nuclei with their incorporation into the structure of the Li metal lattice. Herein the final deposition morphology tightly relies on the Li nucleation and early growth. [14] Figuring out the Li nucleation and early growth is critical to further explore the dendrite inhibition strategies for safe and long-lifespan LMBs. Recently, many insightful and influential models have been proposed to understand the process of Li deposition from nucleation to early growth. [15] Specifically, 1) heterogeneous model describes the heterogeneous nucleation and early growth behavior; 2) surface diffusion model demonstrates Lithium (Li) metal is one of the most promising alternative anode materials of next-generation high-energy-density batteries demanded for advanced energy storage in the coming fourth industrial revolution. Nevertheless, disordered Li deposition easily causes short lifespan and safety concerns and thus severely hinders the practical applications of Li metal batteries. Tremendous efforts are devoted to understanding the mechanism for Li deposition, while the final depositio...

Lithium metal is recognized as one of the most promising anode materials owing to its ultrahigh theoretical specific capacity and low electrochemical potential. Nonetheless, dendritic Li growth has dramatically hindered the practical applications of Li metal anodes. Realizing spherical Li deposition is an effective approach to avoid Li dendrite growth, but the mechanism of spherical deposition is unknown. Herein, a diffusion‐reaction competition mechanism is proposed to reveal the rationale of different Li deposition morphologies. By controlling the rate‐determining step (diffusion or reaction) of Li deposition, various Li deposition scenarios are realized, in which the diffusion‐controlled process tends to lead to dendritic Li deposition while the reaction‐controlled process leads to spherical Li deposition. This study sheds fresh light on the dendrite‐free Li metal anode and guides to achieve safe batteries to benefit future wireless and fossil‐fuel‐free world.

Lithium (Li) metal‐based battery is among the most promising candidates for next‐generation rechargeable high‐energy‐density batteries. Carbon materials are strongly considered as the host of Li metal to relieve the powdery/dendritic Li formation and large volume change during repeated cycles. Herein, we describe the formation of a thin lithiophilic LiC6 layer between carbon fibers (CFs) and metallic Li in Li/CF composite anode obtained through a one‐step rolling method. An electron deviation from Li to carbon elevates the negativity of carbon atoms after Li intercalation as LiC6, which renders stronger binding between carbon framework and Li ions. The Li/CF | Li/CF batteries can operate for more than 90 h with a small polarization voltage of 120 mV at 50% discharge depth. The Li/CF | sulfur pouch cell exhibits a high discharge capacity of 3.25 mAh cm−2 and a large capacity retention rate of 98% after 100 cycles at 0.1 C. It is demonstrated that the as‐obtained Li/CF composite anode with lithiophilic LiC6 layers can effectively alleviate volume expansion and hinder dendritic and powdery morphology of Li deposits. This work sheds fresh light on the role of interfacial layers between host structure and Li metal in composite anode for long‐lifespan working batteries.