High-throughput first-principles-calculations based estimation of lithium ion storage in monolayer rhenium disulfide

Abstract

Two-dimensional materials are promising candidates for lithium ion battery anodes due to their large surface to volume ratio. The distorted T′ phase of the rhenium disulfide crystal makes the study of lithium binding more complex than for other two-dimensional materials with symmetric crystal structures. Here we explore the lithium ion storage capacity of monolayer rhenium disulfide by first-principles based calculations. We employ hardwareaccelerator-assisted high-throughput calculations, using a van der Waals density-functionaltheory based 'structure search' technique, to emulate the lithiation process. Exploring 2000 structures, each containing 49 to 98 atoms, we find the most stable lithiated structures for various lithium concentrations. We then design a delithiation algorithm and apply it to those lithiated structures for the estimation of the reversible specific capacity. Despite possessing high molar mass, a reasonably high specific capacity (214.13 mAh/g) and opencircuit voltage (0.8 V), in agreement with experimental results, make rhenium disulfide a promising alternative anode material.

Machine-Intelligence-Driven High-Throughput Prediction of 2D Charge Density Wave Phases

“…have been implemented here. The AIRSS Shake & Relax algorithm and its highly parallel masterslave implementation are similar to that of our previous works 12,13 . To accelerate the DFT calculations, hardware-accelerators have been employed extensively.…”

Thermodynamic Insights into Polymorphism-Driven Lithium-Ion Storage in Monoelemental 2D Materials

“…However, the calculated specific capacities are known to be drastically overestimated when compared to empirical findings. , One reason for this could be using the “uniform adsorption” model in most of these studies. Recently, multiple high-throughput structure-searching-based computational studies have demonstrated the “uniform adsorption” model’s limits while predicting the most stable cation-adsorbed phase and the specific capacity. , Another possible reason is that these studies cannot incorporate the nonideal effects of multiple charging–discharging cycles, such as bond breaking and formation, phase change of adsorbent, irreversible Li adsorption, electroplating, and so on. In such cases, the uniform-adsorption-predicted theoretical specific capacity might match experimental values for the first few cycles, but rapid capacity fading would soon reduce the quantity to a much lower reversible “effective capacity” which we have previously demonstrated for monolayer ReS 2 . , …”

“…Such phase change (2H to 1T) with lithiation has already been reported for monolayer MoS 2 , , whereas in-situ and ex-situ microscopy studies have revealed semireversible bond cleavage and Li 2 S and other compound formation in the case of MoS 2 and NbS 2 electrodes. − Traditional computational studies lack the machinery to predict and explain such phenomena. Our recent top-down (starting with a known crystal structure of the host and adding Li ions to its surface) structure-searching-based study has been partially successful for ReS 2 and MoS 2 in this regard . Calculation of the formation energy of lithiated electrode compounds as a function of Li concentration and subsequent construction of the convex hull (i.e., thermodynamic assessment of the Li-electrode composition space) has become a popular tool to predict the globally most stable lithiated phases and concurrently the figure of merits. ,,− Forcefully charging the electrode beyond the global energy minimum can induce irreversible changes that could ultimately result in significant capacity fading and even disintegration of the electrode material.…”

“…This kind of convex hull can be used as a “map” by experimentalists that allow drawing a fair comparison of the thermodynamic stability of different lithiated monoelemental 2D phases, in terms of both Li concentration and polymorphism, making it easier to synthesize and test these systems. On the other hand, top-down structure-searching-based studies begin with an individual phase and predict the most stable lithiated structure at a particular Li concentration, which often turns out to be not a uniformly adsorbed but a severely deformed system. ,, Once an estimate of the global minimum is obtained through a bottom-up search with a small number of atoms, the precise local minima can be determined with a many-atom top-down structure search.…”

Interface Structure in Li-Metal/[Pyr14][TFSI]-Ionic Liquid System from ab Initio Molecular Dynamics Simulations

“…This PBE-D3 level of DFT has been validated for several molecular systems, including DFT-MD simulations of metal-organics and Li-ion battery interfaces in particular. 27,28,[48][49][50] The energy cutoff for the plane-wave basis expansion was chosen at 500 eV, which was verified to provide converged forces by a test calculation at 600 eV. For the bulk Brillouin zone integration, a Γ-centered k-point mesh was used in all DFT-MD simulations within the supercell.…”