Lithiophilic Mo₂C Clusters‐Embedded Carbon Nanofibers for High Energy Density Lithium Metal Batteries

Abstract

Lithium metal anodes are widely regarded as the ideal candidate for the next generation of high‐energy‐density lithium batteries. Here, a 3D host made of lithiophilic Mo2C clusters‐embedded carbon nanofibers (Mo2C@CNF) is developed. The uniformly dispersed clusters and large specific surface areas of Mo2C@CNF provide numerous nucleation sites for lithium deposition. Mo2C clusters exhibit ultralow nucleation overpotential compared to MoO2, which is also supported by density functional theory calculations. Furthermore, the transition metal element serves as a catalyst for the formation of a stable and robust solid electrolyte interphase layer containing LiF on Mo2C@CNF, effectively mitigating the occurrence of dead lithium and enhancing the Coulombic efficiency during prolonged operation. As a result, the Mo2C@CNF composite delivers superior electrochemical performance (>1600 h) at 1 mA cm−2 and lower nucleation overpotential (13 mV) for lithium plating. The Li/Mo2C@CNF anode coupled with the commercial LiFePO4 cathode exhibits excellent cycling stability (300 cycles at 1 C) and high rate capability at low N/P ratios.

Structural Design of 3D Current Collectors for Lithium Metal Anodes: A Review

“…Compared to metal‐based materials, carbon materials show light weight, flexibility, wide range of sources, controllable specific surface area, pore structure, etc [46] . To date, various carbon‐based materials have been prepared as the host for Li metal, such as the commercial carbon cloths (CC), [47] carbon nanotubes (CNTs), [48] carbon fibers/nanofibers (CFs/CNFs), [7a,49] graphene materials, [46a,50] and hollow carbon [51] etc.…”

“…(3) Introduction of lithophilic inorganic compounds: there are conversion reactions between different inorganic compounds and Li that can be exploited to increase the lithiophilicity of carbon‐based materials, as well as provide nucleation sites for Li deposition. Until now, highly lithophilic compounds used as Li‐metal lithiophilic seeds, including metal oxides (such as ZnO, [49a,78] MnO 2 , [79] TiO 2 [80] ), nitrides (such as CoN, [81] NiN, [81] ) fluorides (such as MgF 2 [82] ), sulfides (such as ZnS, [49c] MoS 2 [83] ), carbides (such as MoC, [7a] LiC, [84] TiC, [85] FeXC [86] ), have been reported. In addition,alloy reaction of pure metal (such as Ag, [87] Au, [49b] Sn [88] ) etc.…”

Optimizing Current Collector Interfaces for Efficient “Anode‐Free” Lithium Metal Batteries

“…[140] The 3D Cu 2 S nanosheet arrays provide bet-ter interfacial contact and structural design for AFLMBs, which helps to reduce local current density. [141][142] Huang et al [143] reported that a free-standing 3D host of lithiophilic Mo 2 C clustersembedded carbon nanofibers (Mo 2 C@CNF) tested with LFP fullcells resulted in an energy density of 378 Wh kg −1 .…”

Synergistic Ion Sieve and Solvation Regulation by Recyclable Clay-Based Electrolyte Membrane for Stable Zn-Iodine Battery

“…Large-scale energy storage based on secondary batteries is indispensable for the collection of electricity intermittently generated from renewable resources, such as sun, wind, and tide, to reduce environmental pollution and greenhouse gas emission. − To date, although commercial lithium ion batteries (LIBs) have been widely used as rechargeable devices for large-scale energy storage owing to their high energy density, safety issues regarding the flammable organic electrolyte and price concerns derived from the scarce resources of Li-salt severely restrict their sustainable utilization. − Comparably, aqueous batteries, e.g., zinc–iodine batteries, are believed to be an ideal alternative due to the elemental abundance, high theoretical capacity, simple manufacturing process, and stable potential plateau of both zinc (Zn) metal anode and iodine cathode. − , However, the state-of-the-art Zn-iodine batteries exhibit low Coulombic efficiency and rapid capacity decay and are therefore still far away from satisfactory for practical applications. The main obstacles are attributable to (i) the unstable Zn anode involving nonuniform electric field-induced dendrite growth, irreversible capacity decay, and even short circuit; , (ii) the generation of dissoluble polyiodides intermediates (e.g., I 3 – , I 5 – ) that lead to shuttle effects across the separator (cathode loss) and the further corrosion of Zn anode. , …”