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In the search for new additives (anion receptors) in Li-ion battery electrolytes especially for LiPF 6 and LiClO 4 , we have theoretically designed boron-based complexes by coupling with different heterocyclic ligands. The validation of the formation of modeled compounds involves reproduction of available experimentally reported absolute magnetic shielding and chemical shift values for different boron complexes. As compared to the commonly used tris(pentafluorophenyl) borane, our designed compounds suggest that the complexes like B[C 2 HBNO(CN) 2 ] 3 , B[C 2 HBNS(CN) 2 ] 3 , and B[C 4 H 3 BN(CN) 2 ] 3 are promising additives.

Abstract: Zintl ions constitute a special type of naked anionic clusters, mainly consisting of Group 13, 14, and 15 elements of the Periodic Table. Due to the presence of multiple negative ions, the chemistry of Zintl ions is unique. They not only form Zintl phases with alkali and alkaline‐earth metal cations, but also form organo‐Zintl clusters with distinct properties. By first‐principles calculations based on density functional theory, we have designed a new deltahedral organo‐Zintl cluster with Ge94− as the core and aromatic heterocyclic compounds as ligands. Calculations on such complexes show that they form a special class of system known as a superhalogen (SH), with a high vertical detachment energy of 4.9 eV. The density of states (DOS), partial DOS, and different molecular orbitals give additional information about the bonding features of the complexes. [ABSTRACT FROM AUTHOR]

The assembly of atoms leads to the formation of clusters. These clusters have a tendency to gain their stability by forming either cations or anions. Among the anionic clusters, Zintl ions with multiple negative charges are a special type of inorganic complex generally formed from group 13, 14 and 15 elements in the periodic table. On the other hand, superhalogens are neutral molecules which have high electron affinity. Between the two different types of molecules, the former stabilized in the neutral state by forming a phase with alkali metal atoms, while the latter prefers the anionic state. Using first principle calculations, we show that it is also possible to design superhalogens having a Zintl core by functionalizing with suitable ligands like CF3, CN and NO2. The vertical detachment energies of these complexes indicate that they can be classified as superhalogens. The stability of these complexes is explained in terms of the jellium model. Density of states, partial density of states and natural localized molecular orbitals (NLMO) of these molecules lend additional information on the structure and bonding of these complexes. [ABSTRACT FROM AUTHOR]

Inorganic superhalogens are commonly used as anionic counterparts in Li-ion batteries. In an endeavour to prepare better electrolytes, we have modelled the anionic part with different organic heterocyclic-based superhalogens. First principles calculations on those organic superhalogens reveal that the Li-binding energy is at par with that of the Li-salt of a common electrolyte. Out of five different halogen free organic heterocycles, Li[C3BN2(NO2)4] and Li[C2BNO(NO2)3] are found to be mostly suitable as electrolytes in Li-ion batteries. Molecular dynamics simulation studies on C2BNO(NO2)3−, C3BN2(NO2)4−, Li[C2BNO(NO2)3] and Li[C3BN2(NO2)4] also reveal that the structures are dynamically stable. [ABSTRACT FROM AUTHOR]

Most electrolytes currently used in Li-ion batteries contain halogens, which are toxic. In the search for halogen-free electrolytes, we studied the electronic structure of the current electrolytes using first-principles theory. The results showed that all current electrolytes are based on superhalogens, i.e., the vertical electron detachment energies of the moieties that make up the negative ions are larger than those of any halogen atom. Realizing that several superhalogens exist that do not contain a single halogen atom, we studied their potential as effective electrolytes by calculating not only the energy needed to remove a Li+ ion but also their affinity towards H2O. Several halogen-free electrolytes are identified among which Li(CB11H12) is shown to have the greatest potential. [ABSTRACT FROM AUTHOR]

No organic molecules with electron affinities near or above those of halogens are known. We show for the first time that aromaticity rules can be used to design molecules with electron affinities far exceeding those of halogen atoms either by tailoring the ligands of cyclopentadienyl or by multiple benzoannulations of cyclopentadienyl in conjunction with the substitution of CH groups with isoelectronic N atoms. Results based on density functional theory revealed that the electron affinities of some of these organic molecules can reach as high as 5.59 eV, thus opening the door to new class of superhalogens that contain neither a metal nor a halogen atom. [ABSTRACT FROM AUTHOR]

A correction to the article "Aromatic Superhalogens," that was published in a previous issue is presented.