The potential application of borazine (B3N3)-doped nanographene decorated with halides as anode materials for Li-ion batteries: a first-principles study

Exploring the electron donor-acceptor duality of B3N3 in noncovalent interactions

Boron nitrides are very important and are used as lubricants, insulating agents, etc. Interactions of such systems with small molecules are important. This study examined the potential of B3N3 (triboron trinitride) to act as both an electron acceptor and an electron donor in the formation of noncovalent interactions. The anisotropic electronic distribution observed in the electrostatic potential map supported the B3N3's ability to exhibit the predicted electron donor-acceptor duality. Further computational investigations on optimized gas-phase complexes of B3N3:(NH3)n=1-3, B3N3:(NCH)n=1-6, B3N3:(N2H2)n=1-3 and (B3N3)2 confirmed that the B3N3 molecule can participate in B⋯N triel bonding interactions and H···N hydrogen bonding interactions. These energetically stable complexes are primarily governed by electrostatic and polarization interactions.

Li adsorption and diffusion on the surfaces of molybdenum dichalcogenides MoX2 (X = S, Se, Te) monolayers for lithium-ion batteries application: a DFT study

CONTEXT

We study some of the most high performance electrode materials for lithium-ion batteries. These comprise molybdenum dichalcogenide MoX2 (molybdenum disulfide MoS2, molybdenum diselenide MoSe2, molybdenum ditelluride MoTe2). The stability is studied by calculating cohesive energy and formation energy. Structural, electronic, and electrical properties are well defined, and these structures show a direct gap. Lithium adsorption at different sites, theoretical storage capacity, and lithium diffusion path are determined. Our study findings suggest that the adsorption of Li on the preferred site on the surface of the MoX2 monolayer maintains its semiconductor behavior. Comparing the activation energy barrier of these structures with other monolayers such as graphene or silicene, we found that MoX2 shows low lithium diffusion energy and good storage capacity, which indicates that the MoX2 is well suited as an anode material for lithium-ion batteries. Our research can offer new ideas for experimental and theoretical design and new anode materials for lithium-ion batteries (LIB).

METHODS

The studies were performed with Quantum ESPRESSO package based on density functional theory (DFT), plane waves, and pseudopotentials (PWSCF) to calculate the physical properties of MoX2 (X = S, Se, Te), lithium adsorption, and diffusion on their surfaces and the storage capacity of these structures. The BoltzTraP code is used to calculate thermoelectric properties.

Hydrogen adsorption on inorganic benzenes decorated with alkali metal cations: theoretical study

Hydrogen adsorption on different benzenes, both organic and inorganic, decorated with Li cations (Li+) was systematically studied by using quantum chemistry techniques. Our calculations demonstrate that Li+-decoration enhances the hydrogen storage ability of the complexes. MP2 calculations reveal that one to five hydrogen molecules per Li+ have high adsorption energies (Ead), up to -4.77 kcal mol-1, which is crucial for effective adsorption/desorption performance. The assessed hydrogen capacity of studied complexes is in the range of 10.0-10.6 wt%. SAPT2 calculations confirmed that induction and electrostatic interactions play the major role for H2 adsorption of the investigated systems, whereas London dispersion contributes to Ead moderately only in the cases of large number of hydrogen molecules adsorbed. Independent gradient model (IGM) analysis showed that there exists non-covalent bonding between Li+ and H2. The obtained van't Hoff desorption temperatures substantially exceed the temperature of liquid nitrogen. Ab initio molecular dynamics simulations confirmed the stability of the studied complexes. Our investigations establish the high potential of the studied complexes for usage in systems for hydrogen storage.