The Role of Geometric Sites in 2D Materials for Energy Storage

Abstract

Two-dimensional nanostructures may effectively be utilized as electrode materials for lithium/sodium-ion batteries to enhance the energy and power densities and cycling stability, and to satisfy the increasing demands of electrical vehicles and power stations. This review introduces the ''geometry-driven'' concept to illuminate the mechanisms related to various geometric sites in 2D materials for improving their electrochemical performance. The geometric sites of 2D materials are categorized into point-like, line-like, and plane-like defects. The electronic structures of geometric sites are then discussed. Hierarchical materials constructed from 2D materials, such as 3D crumpled nanoparticles, nanoflowers, and heterostructures, are highlighted. A summary of applications of the in situ transmission electron microscopy (TEM) technique is presented toward understanding the mechanisms of geometric-site effects in 2D materials. Finally, some perspectives on the geometry concept for material designs, theoretical calculations for performance prediction, and modern in situ TEM techniques for uncovering electrochemical mechanisms are discussed.

Defects on carbons for electrocatalytic oxygen reduction

“…213 More recently, the importance of defect coordination chemistry in oxygen-involving electrocatalysis has been continuously demonstrated and summarized by several groups. 67,[214][215][216][217][218] For example, the electronic state is asymmetrically tailored at the vacancy or reconstructed carbon defect sites of graphene. This modification not only could enhance the ORR performance, but also be functional for other electrocatalysis, such as the OER and HER.…”

“…This modification not only could enhance the ORR performance, but also be functional for other electrocatalysis, such as the OER and HER. 67,218 Besides the defects themselves could catalyze the electrochemical reactions (according to the proposed catalysis mechanism based on defect structures), defects are also capable of providing unique sites for trapping metallic species. 9,113,219 Due to the different structures and sizes of the defects, one or more metal atoms might be trapped into the specific defect site.…”

Insight into anomalous hydrogen adsorption on rare earth metal decorated on 2-dimensional hexagonal boron nitride: a density functional theory study

“…The study of geometric sites for hydrogen interaction with metal atoms on a two-dimensional (2D) substrate material is one of the most recent and emerging areas for developing materials for energy storage and catalysis. 12…”

Enhanced Li‐Ion‐Storage Performance of MoS2 through Multistage Structural Design

“…[10] This inspires us to consider: whether the multistage structural design concept applicable to the folded proteins can be employed herein to create the advanced electrode materials for LIBs. [13][14][15][16] In recent years, various MoS 2 composites, [17][18][19][20][21][22][23][24][25][26][27] including MoS 2 /C, [19,20,23,24] SnS 2 /MoS 2 /CFC, [21] MoO 2 @MoS 2 [22] and S-MoS 2 @α-Fe 2 O 3 [26] have been widely exploited as important anode materials for lithium ion batteries (see Table S1). [13][14][15][16] In recent years, various MoS 2 composites, [17][18][19][20][21][22][23][24][25][26][27] including MoS 2 /C, [19,20,23,24] SnS 2 /MoS 2 /CFC, [21] MoO 2 @MoS 2 [22] and S-MoS 2 @α-Fe 2 O 3 [26] have been widely exploited as important anode materials for lithium ion batteries...…”