Advances in the Design of 3D‐Structured Electrode Materials for Lithium‐Metal Anodes

Abstract

In view of their high energy densities, absence of memory effects, and high round-trip energy efficiencies, conventional lithium-ion batteries (LIBs) are widely used on scales ranging from compact electronic devices to grid systems [8,9] but are currently reaching their maximal capacity, as their specific/volumetric energy densities are limited by the use of heavy metal-based active host materials. [10,11] The use of Li as a high-energy active anode material is a possible solution to this problem, as this metal exhibits a high theoretical capacity of ≈3860 mAh g −1 and a low redox potential (−3.040 V vs the standard hydrogen electrode). [12,13] However, the Li-metal anode (LMA) has some fatal drawbacks originating from highaspect-ratio metal growth, e.g., continuous electrolyte consumption, Coulombic efficiency (CE) reduction, elevated cell polarization due to side reactions producing dead Li, and safety issues caused by electrode short-circuiting. [14,15] Recently, these drawbacks have been addressed by several approaches such as electrode design and electrolyte engineering. [16-21] Metal growth can be described by a first-order linear equation as Although the lithium-metal anode (LMA) can deliver a high theoretical capacity of ≈3860 mAh g −1 at a low redox potential of −3.040 V (vs the standard hydrogen electrode), its application in rechargeable batteries is hindered by the poor Coulombic efficiency and safety issues caused by dendritic metal growth. Consequently, careful electrode design, electrolyte engineering, solid-electrolyte interface control, protective layer introduction, and other strategies are suggested as possible solutions. In particular, one should note the great potential of 3D-structured electrode materials, which feature high active specific surface areas and stereoscopic structures with multitudinous lithiophilic sites and can therefore facilitate rapid Li-ion flux and metal nucleation as well as mitigate Li dendrite formation through the kinetic control of metal deposition even at high local current densities. This progress report reviews the design of 3D-structured electrode materials for LMA according to their categories, namely 1) metal-based materials, 2) carbon-based materials, and 3) their hybrids, and allows the results obtained under different experimental conditions to be seen at a single glance, thus being helpful for researchers working in related fields.

Recent Progress of Porous Materials in Lithium‐Metal Batteries

“…[26][27][28][29] High electrochemical performance of LMBs requires high-Coulombic-efficiency (CE), dendrite-free, and low-volume-expansion Li-metal anodes. To meet these critical requirements, tremendous approaches have been pursued in the past several years, mainly including, but not limited to, adjusting the architecture of current collectors, [30][31][32][33][34][35][36][37][38] optimizing the composition of electrolytes, [39][40][41][42][43][44][45][46] establishing an artificial solid electrolyte interface (SEI), [47][48][49][50] modifying the spectators, [51,52] and using solid-state or polymeric electrolytes. [53][54][55] The introduction of different strategies effectively mitigated the Li dendrite growth and significantly improved the CE, making the electrochemical performance of current LMBs obtain enormous progress.…”

Self‐Healing Properties of Alkali Metals under “High‐Energy Conditions” in Batteries

“…[14] All the abovementioned limitations can be overcome or reduced if dendrite growth/breakage can be prevented during the deposition/ dissolution process. Many studies have been reported on the construction of dendrite-free metal anodes: a) fabrication of modified electrodes or metal substrate surfaces, [15][16][17][18][19][20][21][22][23][24] b) synthesis of new electrolytes, [25][26][27][28][29] c) use of solid electrolytes, [22,[30][31][32] and d) improvement of the electrode-electrolyte interface. [9,15,33,34] However, these studies have rarely focused on the properties, such as the stability of dendrites during charging and discharging, of dendrites.…”

In Situ and Operando Characterizations of 2D Materials in Electrochemical Energy Storage Devices

“…In addition, various strategies for stabilizing the interface have been proposed, including modification of the electrolyte compositions and design of nanostructured or coated electrodes. [ 86–91 ]…”