Lithiophilic 3D Nanoporous Nitrogen‐Doped Graphene for Dendrite‐Free and Ultrahigh‐Rate Lithium‐Metal Anodes

Abstract

discharge and charge. These problems cause early cell death, poor Coulombic efficiency (CE), rapid cycling capacity decay, and catastrophic thermal runaway. [9][10][11][12] To overcome the above thorny issues, extensive endeavors have been revived and a number of strategies have been proposed and practiced. For example, strengthening the solid electrolyte interphase (SEI) films by engineering liquid electrolytes with functional additives (LiNO 3 , Cs + , LiF, etc.) or employing solid electrolytes to prevent the Li dendrites. [13][14][15][16][17][18][19] However, these efforts cannot accommodate the infinite volume changes of Li metal during lithium stripping/plating, which can damage the contact interfaces between the electrolytes and Li anodes for continuous charge/discharge cycling. Porous and conductive scaffolds are expected to simultaneously suppress the Li dendrite growth and minimize the volume changes of Li metal electrodes. [20][21][22][23][24][25][26] Such host materials with a large specific surface area not only lower the local effective current density to form a uniform Li-ion flux but also provide an ample space to accommodate Li. Multifarious porous metal foams, such as 3D porous Cu foils and Cu-Ni core-shell nanowire networks, have behaved as effective hosts of Li. [23,27,28] However, the high mass density of these porous metals dramatically reduces the overall energy density of the composite electrodes, and dissipates the advantages of Li-metal anodes in specific capacity and energy density. In this respect, it is highly desirable to develop lightweight, flexible, conductive, and porous host materials with a lower interfacial energy with lithium.Lightweight porous carbon materials, including carbon nanotube and graphene exhibit distinct advantages over porous metals. [10,[29][30][31][32][33] The appealing characteristics of low mass density, excellent electrical conductivity, and chemical stability render them as promising host materials of Li anodes. [34][35][36][37][38][39][40][41] However, these carbon skeletons are usually lithium-phobic and require Li seed growth or additional lithiophilic surface modification to load Li. [42][43][44][45][46][47] Additionally, conventional porous carbon hosts with relatively large pore size (>10 µm) cannot efficiently dissipate large current densities due to limited surface areas, deteriorating the high rate performance of Limetal anodes. [29,31,36] Technically, it is difficult to efficiently pack 1D carbon nanotube and 2D graphene sheets into a 3D porous structure that can simultaneously achieve high porosity, largeThe key bottlenecks hindering the practical implementations of lithiummetal anodes in high-energy-density rechargeable batteries are the uncontrolled dendrite growth and infinite volume changes during charging and discharging, which lead to short lifespan and catastrophic safety hazards. In principle, these problems can be mitigated or even solved by loading lithium into a high-surface-area, conductive, and lithiophilic porous scaffold. However, ...

Two‐dimensional materials of group‐IVA boosting the development of energy storage and conversion

“…But, the lack of suitable electrode materials strictly hinders the development of metal‐ion batteries. Graphene, a class of superior thermal and electrical conductors, can not only act as a conductive filler but also form the desirable nanocomposite electrode structures in conjunction with carbon nanotubes, transition metal oxides, and so forth to enhance ion infusion, electron transfer, and alleviate the volume expansion 80‐82,90,91‐96 . The strategy for the feasible nanostructured assembly of a three‐dimensional porous graphene/niobia (Nb 2 O 5 ) composite was applied by Sun et al 83 to prepare the 3D electrode architecture delivering high areal capacity and high‐rate capability at practical levels of mass loading.…”

“…Graphene, a class of superior thermal and electrical conductors, can not only act as a conductive filler but also form the desirable nanocomposite electrode structures in conjunction with carbon nanotubes, transition metal oxides, and so forth to enhance ion infusion, electron transfer, and alleviate the volume [79] expansion. [80][81][82]90,[91][92][93][94][95][96] The strategy for the feasible nanostructured assembly of a three-dimensional porous graphene/ niobia (Nb 2 O 5 ) composite was applied by Sun et al 83 to prepare the 3D electrode architecture delivering high areal capacity and high-rate capability at practical levels of mass loading. Subsequently, Zhao et al 84 found that densely packed Li x M/graphene foils (M = Si, Sn, or Al) would serve as air-stable and freestanding anodes guaranteeing stable structures and exceptional cyclabilities ( Figure 10).…”

Flexible Amalgam Film Enables Stable Lithium Metal Anodes with High Capacities

“…Instead, the ex situ construction of an artificial protection layer on Li is a more versatile technique to obtain desired compositions and structures. Carbon materials and polymers are frequently employed to build physical layers for preventing dendrite penetration in Li anodes . The flexibility of these materials effectively accommodates volume fluctuation of the underlying anode upon Li plating/stripping…”

Superlithiophilic Amorphous SiO2–TiO2 Distributed into Porous Carbon Skeleton Enabling Uniform Lithium Deposition for Stable Lithium Metal Batteries

“…[2,[6][7][8][9][10][11] However, even with the aid of these interfacial layers, uniform deposition is difficult as it is dependent on a plethora of external factors including ion diffusion, screw dislocation of atoms, and the morphology of the electrode surface. [14][15][16][17][18][19][20][21][22][23][24][25] This specific technique offers several advantages: [26] 1) the porous structure reduces the local current density and ensures sufficient Li ion flux; 2) the porous 3D skeleton accommodates the volumetric change of the Li anode during the plating and stripping progress; 3) Li is deposited on the interior of the 3D matrices, but not directly on the surface of the electrode, thus prohibiting dendrite growth. [14][15][16][17][18][19][20][21][22][23][24][25] This specific technique offers several advantages: [26] 1) the porous structure reduces the local current density and ensures sufficient Li ion flux; 2) the porous 3D skeleton accommodates the volumetric change of the Li anode during the plating and stripping progress; 3) Li is deposited on the interior of the 3D matrices, but not directly on the surface of the electrode, thus prohibiting dendrite growth.…”