Understanding the Role of Dopant Metal Atoms on the Structural and Electronic Properties of Lithium-Rich LiNiMnO Cathode Material for Lithium-Ion Batteries.

Improving the stability of lithium-rich cathode materials is important in refining the overall performance of lithium-ion batteries. Here, we have proposed doping of different metal atoms such as K, Ca, Cd, and Al in different sites of LiNiMnO, and we have investigated their structural and electronic properties using first-principles calculations. We found that the Ni ions in the pristine LiNiMnO structure maintained the +3 oxidation state for a longer time and resulted in the structural deformation during the long cycling process.

Methanol decomposition reactions over a boron-doped graphene supported Ru-Pt catalyst.

The decomposition of methanol is currently attracting research attention due to the potential widespread applications of its end products. In this work, density functional theory (DFT) calculations have been performed to investigate the adsorption and decomposition of methanol on a Ru-Pt/boron doped graphene surface. We find that the most favorable reaction pathway is methanol (CH3OH) decomposition through O-H bond breaking to form methoxide (CH3O) as the initial step, followed by further dehydrogenation steps which generate formaldehyde (CH2O), formyl (CHO), and carbon monoxide (CO).

Improved Interfacial Properties of MCMB Electrode by 1-(Trimethylsilyl)imidazole as New Electrolyte Additive To Suppress LiPF Decomposition.

Trace water content in the electrolyte causes the degradation of LiPF, and the decomposed products further react with water to produce HF, which alters the surface of anode and cathode. As a result, the reaction of HF and the deposition of decomposed products on electrode surface cause significant capacity fading of cells. Avoiding these phenomena is crucial for lithium ion batteries.

First principles study of organic sensitizers for dye sensitized solar cells: effects of anchoring groups on optoelectronic properties and dye aggregation.

We have designed a new set of D-π-A type organic dye sensitizers with different acceptor and anchoring groups, and systematically investigated their optoelectronic properties for efficient dye sensitized solar cell applications. Particularly, we have focused on the effects of anchoring groups on the dye aggregation phenomenon. TDDFT results indicate that the dyes with CSSH anchoring groups exhibit improved optoelectronic properties compared to other dyes.

A First Principles study on Boron-doped Graphene decorated by Ni-Ti-Mg atoms for Enhanced Hydrogen Storage Performance.

We proposed a new solid state material for hydrogen storage, which consists of a combination of both transition and alkaline earth metal atoms decorating a boron-doped graphene surface. Hydrogen adsorption and desorption on this material was investigated using density functional theory calculations. We find that the diffusion barriers for H atom migration and desorption energies are lower than for the previously designed mediums and the proposed medium can reach the gravimetric capacity of ~6.

Oxidative decomposition of propylene carbonate in lithium ion batteries: a DFT study.

This paper reports an in-depth mechanistic study on the oxidative decomposition of propylene carbonate in the presence of lithium salts (LiClO4, LiBF4, LiPF6, and LiAsF6) with the aid of density functional theory calculations at the B3LYP/6-311++G(d,p) level of theory. The solvent effect is accounted for by using the implicit solvation model with density method. Moreover, the rate constants for the decompositions of propylene carbonate have been investigated by using transition-state theory.

Theoretical study of the reductive decomposition of ethylene sulfite: a film-forming electrolyte additive in lithium ion batteries.

The role of ethylene sulfite (ES) as an electrolyte additive for lithium ion batteries is explained by investigating the one- and two-electron reductive decomposition of ES and (ES)Li(+)(PC)(n) (n = 0-2), both in vacuum and solvent, with the aid of high-level density functional theory calculations. The open-chain radical, which is formed as a result of reduction of ES in solvent without first being coordinated with Li(+), is further stabilized by a dissolved lithium ion. The resulting more stable intermediate releases a somewhat large amount of energy, which is utilized in the formation of a subsequent radical anion.