New Findings on an Old Question: Can Defect‐Free Graphene Monolayers be Superior Metal‐Ion Battery Anodes?

Abstract

Graphene has numerous extraordinary properties and applications, ranging from water purification to energy storage. Previous studies identified that defect‐free graphene monolayers cannot be adopted as lithium‐ion battery anodes. Approaches, such as functionalization and introducing defects in graphene, have been employed to improve its performance in energy storage. However, defects in graphene boost dendrite growth, resulting in safety issues and fast power losses in batteries. Herein, by adopting state‐of‐the‐art first‐principles calculations, orbital theory, and transition state theory, it is found that defect‐free graphene monolayers are a promising potassium‐ion battery (KIB) anodes, however, they cannot be employed as lithium‐/sodium‐/magnesium‐/calcium‐/zinc‐/aluminum‐ion battery anodes. The evidence of adsorption energy and electron transfer indicates that van der Waals interactions dominate the adsorption of K atoms while delocalized electrons neutralize repulsion between K ions. The KIB anode delivers a high capacity of 1487.7 mA h g−1 and ultrafast charging/discharging rates. Transition state theory results demonstrate that its ultrahigh classic diffusion constants achieve 2.36 × 1011/1.55 × 109 s−1, its Wigner zero‐point‐energy‐/tunneling‐corrected diffusion constants approach 2.38 × 1011/1.56 × 109 s−1, and its low quantum‐mechanical tunneling effects are 0.67%/0.72% under the low/high concentration diffusion of K ions at room temperature. This work offers a more comprehensive understanding of defect‐free graphene.

Constructing Advanced Aqueous Zinc‐Ion Batteries with 2D Carbon‐Rich Materials

“…Although theoretical simulations showed pessimistic attitude toward defect‐free graphene monolayers being zinc anodes, [ 34 ] chemical modification has already made it possible for functionalized graphene to reversibly store Zn 2+ ions as cathode. Liu et al synthesized a holey graphene electrode with high conductivity and dual‐ion storage ability.…”

Rational Design Strategy of Novel Energy Storage Systems: Toward High‐Performance Rechargeable Magnesium Batteries

“…In view of the limited resources and increasing cost of lithium, sodium ions were further considered to be introduced to the hybrid system to construct Mg 2+ /Na + hybrid ion batteries (MNHIBs). [149][150][151][152] Similar to cathodes for LIBs, several cathodes for SIBs can also be employed in MNHIBs. The working principle of MNHIBs is similar to that of MLHIBs, where Na + ions are de-intercalated or intercalated at Na-containing cathode materials during the charging or discharging process, meanwhile, Mg 2+ plating/stripping occurs at Mg anode.…”

Vacancy–vacancy pairs induced new phase formation in carbon boride: A design principle to achieve superior performance Li/Na‐ion battery anodes

“…19,20 However, the pristine graphene is not an ideal anode for most of metal ion batteries due to its poor adsorption ability. 21,22 To overcome the weak binding issue of those metal atoms in pristine graphene, several approaches, such as introducing point defects, 23 functionalizing edges, 24,25 and providing atom substitution, were proposed to boost the performance of graphene. 26 These approaches provide more active site for alkali metal atoms and would effectively promote their adsorption ability.…”

“…Two‐dimensional (2D) materials based anodes in metal‐ion batteries (MIBs), which have outstanding electrochemical activity, 10 are broadly examined, such as graphene and its derivatives, 11–16 MoS 2 , 17 GaS, 18 SnO 2 and GeO 2 19,20 . However, the pristine graphene is not an ideal anode for most of metal ion batteries due to its poor adsorption ability 21,22 . To overcome the weak binding issue of those metal atoms in pristine graphene, several approaches, such as introducing point defects, 23 functionalizing edges, 24,25 and providing atom substitution, were proposed to boost the performance of graphene 26 .…”