The high stability of boron-doped lithium clusters Li5B, Li6B+/− and Li7B: A case of the phenomenological shell model

A theoretical approach to the role of different types of electrons in planar elongated boron clusters

While the stability of planar elongated pure boron clusters is determined by their […σ²⁽ⁿ⁺¹⁾ π₁²⁽ⁿ⁺¹⁾ π₂²ⁿ] electronic configuration, the rectangle model can rationalize the π electronic configuration of rectangle-shaped structures.

Boron Embedded in Metal Iron Matrix as a Novel Anode Material of Excellent Performance

Boron, the most ideal lithium-ion battery anode material, demonstrates highest theoretical capacity up to 12 395 mA h g^-1 when forming Li₅ B. Furthermore, it also exhibits promising features such as light weight, considerable reserves, low cost, and nontoxicity. However, boron-based materials are not in the hotspot list because Li₅ B may only exist when B is in atomically isolated/dispersed form, while the aggregate material can barely be activated to store/release Li. At this time, an ingenious design is demonstrated to activate the inert B to a high specific capacity anode material by dispersing it in a Fe matrix. The above material can be obtained after an electrochemical activation of the precursors Fe₂ B/Fe and B₂ O₃ /Fe. The latter harvests the admirable capacity, ultrahigh tap density of 2.12 g cm^-3 , excellent cycling stability of 3180 mA h cm^-3 at 0.1 A g^-1 (1500 mA h g^-1 ) after 250 cycles, and superlative rate capability of 2650 mA h cm^-3 at 0.5 A g^-1 , 2544 mA h cm^-3 at 1.0 A g^-1 , and 1696 mA h cm^-3 at 2.0 A g^-1 . Highly conductive matrix promoted reversible Li storage of boron-based materials might open a new gate for advanced anode materials.

Structure and stability of small lithium-chloride LinClm(0,1+) (n ≥ m, n = 1–6, m = 1–3) clusters

Detailed theoretical investigations along with the experimental observations of new small chlorine-doped lithium clusters are presented.

First-principle investigation on growth patterns and properties of cobalt-doped lithium nanoclusters

A systematic theoretical investigation on cobalt lithium clusters LinCo [1-12] was performed with a DFT approach. The location of global minima and structural evolution were carried out using the partical swarm optimization method. Li6Co is the transition structure in going from low-coordinated structures to three-dimensional torispherical structures with a cobalt atom enclosed by lithium atoms. Maxima of ∆2 E and E b for LinCo were found at n = 3, 6, 8, 10, indicating that these clusters possess higher relative stability than their neighbors. In comparison with small clusters, n = 1-6, the greater electron transfer from Li-2s to Co-3d within cage-like clusters LinCo (n = 7-12) strengthens the bonding effect between Lin and Co, which is reflected in the Wiberg bond index of Co and atomic binding energy analysis. AdNDP analysis verified the presence of both Lewis bonding elements (1c-2e objects) and delocalized bonding elements (6c-2e, 9c-2e and 10c-2e bonds). It is hoped that this theoretical work will provide favorable information to help understand the influence of dopant transition metal atoms on the properties of lithium-based materials.

A Stochastic Search for the Structures of Small Germanium Clusters and Their Anions: Enhanced Stability by Spherical Aromaticity of the Ge10 and Ge12(2-) Systems

Investigations on germanium clusters in the neutral, anionic, and dianion states Gen(x) (n = 2-12 and x = 0, -1, -2) are performed using quantum chemical calculations with the B3LYP functional and the coupled-cluster singles and doubles [CCSD(T)] methods, in conjunction with the 6-311+G(d) basis set. An improved stochastic method is implemented for searching the low-lying isomers of clusters. Comparison of our results with previous reports on germanium clusters shows the efficiency of the search method. The Ge8 system is presented in detail. The anionic clusters Gen(-/2-) are studied theoretically and systematically for the first time, and their energetics are in good agreement with available experiments. The clusters Ge10, Ge10(2-), and Ge12(2-) are, in their ground state, characterized by large highest occupied molecular orbital-lowest unoccupied molecular orbital gaps, high vertical and adiabatic detachment energies, and substantial average binding energies. The enhanced stability of these magic clusters can consistently be rationalized using the jellium electron shell model and the spherical aromatic character.