Phographene as a High-Performance Anode Material with High Specific Capacity and Fast Li Diffusion: From Structural, Electronic, and Mechanical Properties to LIB Applications

Abstract

The progress of ecofriendly, clean, and sustainable energy resources always demands suitable anode materials for batteries with high structural stability and superior storage capacity. Herein, we use density functional theory predictions to examine the potential features of newly proposed planar membranes consist of 5-, 6- and 8- membered carbon rings, named as α- and β-phographene (PhoG). Our calculations disclose that both α- and β-PhoG structures possess high structural, thermal, and mechanical stability with intrinsic metallic characteristics. We have further extended our calculations of PhoG as a suitable anode material for use in Lithium-ion batteries. Our results reveal the Li adsorption in PhoG is exothermic and the α-PhoG show a higher theoretical specific capacity of Li2.4C6 for Li atoms (892 mAh g–1) compared to the LiC6 of graphite. We also found that both the α- and β-PhoG structures show fast Li mobility with a low diffusion barrier for Li atoms (<0.30 eV) as well as low average open circuit voltage (∼0.26 V). Our findings show that both the PhoG structures, especially α-PhoG, are suitable anode candidates for use in future Li-ion batteries owing to the metallic characteristic combined with the low open circuit voltage, low diffusion barrier, high Li storage capacity, and high thermo-mechanical stability. Our results would supply guidelines to develop better high-capacity anode materials for future Li-ion batteries.

From fundamental to CO2 and COCl2 gas sensing properties of pristine and defective Si2BN monolayers

“…We also noticed that the defective regions in Si 2 BN-Si vac , Si 2 BN-B vac , and Si 2 BN-N vac possess a relatively weaker accumulation of electronic charges. It is confirmed from the ELF analysis that the relatively strong s-bonding states between neighboring atoms in Si 2 BN structures are responsible for superior electronic properties similar to graphenes and other carbon-based 2D materials 5. COCl 2 and CO 2 gas sensing of Si 2 BN-ML 3.3.1.…”

“…where E defect and E perfect are the total energies of the Si 2 BN-ML with specific vacancy defects and pristine surface, respectively, n i is the total number of Si, B and N vacancies and m i is the chemical potential of the individual Si, B and N atoms, which are taken as the bulk energy of diamond Si, alpha B and N. The mechanical stability of the Si 2 BN-ML was analyzed from the linear elastic constants by employing the energy-strain approach as detailed elsewhere. 5,8,10,22,25,52 Then, the elastic modulus tensors (C 11 , C 22 , C 12 and C 66 ) were obtained by fitting the derivative of strain energy to the applied strain.…”

“…1 Although 2D materials have arisen as hopeful candidates for numerous applications, only a few dozen 2D materials have been successfully exfoliated and synthesized. 2 Furthermore, numerous experimental and theoretical studies on different families of 2D materials have been carried out to examine their properties for different potential applications in rechargeable metal-ion batteries as the anode, [3][4][5][6][7][8][9][10] environmental gas monitors, 11,12 biosensors, [13][14][15] supercapacitors, 16 and catalysts. [17][18][19][20] The 2D materials composed of light elements such as B, C, and N have received more attention due to their extraordinary structural and electronic properties, mechanical strength, and adsorption properties in their pristine and defect-filled forms.…”

Computational predictions of two‐dimensional anode materials of metal‐ion batteries

“…Its theoretical capacities are 876.65 (Li), 1,275.12 (Na), and 956.34 (K) mA hr g −1 , with moderate ion migration barriers (≤0.48 eV) and low average OCV (≤0.60 V). Thomas et al performed theoretical calculations on planar carbon materials composed of 5‐, 6‐, and 8‐membered rings, namely, α‐ and β‐phographene (PhoG) . Its high topological defect density caused by the 5‐, 6‐, and 8‐membered rings can enhance the charge transfer between Li and membrane, increasing the percentage of Li adsorption and leading to a higher capacity.…”

Monolayer, Bilayer, and Bulk BSi as Potential Anode Materials of Li‐Ion Batteries

“…Despite all these advantages, the Li storage capacity of graphite (372 mAh g −1 ) nowadays is considered to be much too low for the next generation of LIBs. Planar and buckled C‐allotropes like C‐haeckelites, [2] phographene, [3] and popgraphene [4] can provide superior Li storage capacities combined with favorable metallicity, however, they suffer from high Li diffusion barriers. In the hunt for anode materials with higher Li storage capacity, a variety of bulk materials and nanostructures have been studied.…”