The doping effect on the catalytic activity of graphene for oxygen evolution reaction in a lithium–air battery: a first-principles study

Abstract

A lithium-air battery as an energy storage technology can be used in electric vehicles due to its large energy density. However, its poor rate capability, low power density and large overpotential problems limit its practical usage. In this paper, the first-principles thermodynamic calculations were performed to study the catalytic activity of X-doped graphene (X = B, N, Al, Si, and P) materials as potential cathodes to enhance charge reactions in a lithium-air battery. Among these materials, P-doped graphene exhibits the highest catalytic activity in reducing the charge voltage by 0.25 V, while B-doped graphene has the highest catalytic activity in decreasing the oxygen evolution barrier by 0.12 eV. By combining these two catalytic effects, B,P-codoped graphene was demonstrated to have an enhanced catalytic activity in reducing the O2 evolution barrier by 0.70 eV and the charge voltage by 0.13 V. B-doped graphene interacts with Li2O2 by Li-sited adsorption in which the electron-withdrawing center can enhance charge transfer from Li2O2 to the substrate, facilitating reduction of O2 evolution barrier. In contrast, X-doped graphene (X = N, Al, Si, and P) prefers O-sited adsorption toward Li2O2, forming a X-O2(2-)···Li(+) interface structure between X-O2(2-) and the rich Li(+) layer. The active structure of X-O2(2-) can weaken the surrounding Li-O2 bonds and significantly reduce Li(+) desorption energy at the interface. Our investigation is helpful in developing a novel catalyst to enhance oxygen evolution reaction (OER) in Li-air batteries.

Recent Progress in Electrocatalyst for Li‐O2 Batteries

“…[60] This may help increase the oxygen evolution rate and improve the rate capability of OER. Simultaneously, the boron-doped graphene is found to have good catalytic activity in decreasing the oxygen evolution barrier demonstrated by Ren et al [61] However, the role of boron-doped graphite carbon in improving electrochemical performance of Li-O 2 batteries is only theoretically feasible, requiring experimental validation. Correcting this deficiency, Wu reported the 3D porous B-rGO material with a hierarchical structure prepared by a facile freeze drying method.…”

Adsorption-energy-based activity descriptors for electrocatalysts in energy storage applications

“…As a result, charge transfer has a great effect on catalytic activity. J. Liu et al performed first-principles thermodynamic calculations to study the catalytic activity of X-doped graphene (X = B, N, Al, Si, and P) materials as potential cathodes to lower the charging overpotential [78,79]. They found that Liadsorbed sites on B-doped graphene, as the electronwithdrawing center, enhance charge transfer from Li 2 O 2 to the cathode and thus reduce the O 2 evolution barrier.…”

A Review of Carbon-Composited Materials as Air-Electrode Bifunctional Electrocatalysts for Metal–Air Batteries

“…These non-metal heteroatoms are usually introduced into pure carbon to form RMAB airelectrode catalysts through doping strategies. As identified, dopants can act as a secondary phase; providing adsorption structures for charge transfer and improving electrocatalytic activities of ORR and/or OER [21,22]. Recently, various carbon materials (e.g., porous carbon materials, CNT, graphenes, carbon fibers, carbon xerogel, carbon aerogel, nanocage carbons, carbon nano-onions) have been explored as heteroatom-doped carbon catalysts for BMABs and the results show that these composited carbon materials exhibit desirable characteristics such as desirable pore size/volume, large surface area, and high stability.…”

“…After a series of electrochemical measurements in an assembled primary ZABs, the ORR activity of NFGD was found to be comparable to that of commercial Pt/C (20 wt% Pt on Vulcan XC-72) and superior to those of the other two dual-doped GDs. A first-principle study to theoretically demonstrate the synergistically enhanced catalytic effects of co-doping in B, P co-doped graphene was also carried out to compare with B-doped graphene and P-doped graphene [22].…”