scholarly journals Real-time imaging of Na+ reversible intercalation in “Janus” graphene stacks for battery applications

2021 ◽  
Vol 7 (22) ◽  
pp. eabf0812
Author(s):  
Jinhua Sun ◽  
Matthew Sadd ◽  
Philip Edenborg ◽  
Henrik Grönbeck ◽  
Peter H. Thiesen ◽  
...  
Keyword(s):  
Density Functional ◽  
Lithium Ion ◽  
Density Functional Theory Calculations ◽  
Rechargeable Batteries ◽  
Functional Theory ◽  
Imaging Ellipsometry ◽  
Ionic Bonds ◽  
Abundant Element ◽  
Sodium Storage ◽  
Uniform Pore Size

Sodium, in contrast to other metals, cannot intercalate in graphite, hindering the use of this cheap, abundant element in rechargeable batteries. Here, we report a nanometric graphite-like anode for Na+ storage, formed by stacked graphene sheets functionalized only on one side, termed Janus graphene. The asymmetric functionalization allows reversible intercalation of Na+, as monitored by operando Raman spectroelectrochemistry and visualized by imaging ellipsometry. Our Janus graphene has uniform pore size, controllable functionalization density, and few edges; it can store Na+ differently from graphite and stacked graphene. Density functional theory calculations demonstrate that Na+ preferably rests close to -NH2 group forming synergic ionic bonds to graphene, making the interaction process energetically favorable. The estimated sodium storage up to C6.9Na is comparable to graphite for standard lithium ion batteries. Given such encouraging Na+ reversible intercalation behavior, our approach provides a way to design carbon-based materials for sodium ion batteries.

scholarly journals The influence of heteroatom doping on local properties of phosphorene monolayer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Artur P. Durajski ◽  
Konrad M. Gruszka ◽  
Paweł Niegodajew
Keyword(s):  
Density Functional ◽  
Lithium Ion ◽  
Density Functional Theory Calculations ◽  
Rechargeable Batteries ◽  
Functional Theory ◽  
Heteroatom Doping ◽  
Black Phosphorene ◽  
New Energy ◽  
Local Properties ◽  
Storage Technologies

AbstractNew energy storage technologies that can serve as a reliable alternative to lithium-ion batteries are in the spotlight. Particular attention has been recently devoted to magnesium-ion systems due to the considerable abundance of this element and also due to its promising electro-chemical performance. Our results show that monolayer black phosphorene doped by B, Sc, Co, and Cu atoms possesses good structural stability with the minimal cohesive energy of $$-5.563$$ - 5.563 eV/atom, the adsorption energy per Mg atom ranging from $$-1.229$$ - 1.229 to $$-1.357$$ - 1.357 eV, and the charge transfer from double-side adsorbed single Mg-ions to the B-substituted phosphorene increased by $$\sim$$ ∼ 0.21 $$e^-$$ e - in comparison with pristine phosphorene. The present work demonstrates a potential path for future improvements of phosphorus-based anode materials for Mg-ion rechargeable batteries which were evaluated using first-principles density-functional theory calculations.

Theoretical study of SnS2 encapsulated in Graphene as a promising anode material for K−ion batteries

2021 ◽  
Author(s):  
Xuxin Kang ◽  
Wei Xu ◽  
Xiangmei Duan
Keyword(s):  
Anode Material ◽  
Density Functional ◽  
Open Circuit Voltage ◽  
Electronic Conductivity ◽  
Density Functional Theory Calculations ◽  
Rechargeable Batteries ◽  
Open Circuit ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Low K

Abstract Rechargeable batteries with superior electronic conductivity, large capacity, low diffusion barriers and moderate open circuit voltage have attracted amount attention. Due to abundant resources and safety, as well as the high voltage and energy density, potassium ion batteries (KIBs) could be an ideal alternative to next−generation of rechargeable batteries. Based on the density functional theory calculations, we find that the SnS2 monolayer expands greatly during the potassiumization, which limits its practical application. The construction of graphene/SnS2/graphene (G/SnS2/G) heterojunction effectively prevents SnS2 sheet from deformation, and enhances the electronic conductivity. Moreover, the G/SnS2/G has not only a high theoretical special capacity of 680 mAh/g, but an ultra−low K diffusion barrier (0.08 eV) and an average open circuit voltage (0.22 V). Our results predict that the G/SnS2/G heterostructure could be used as a promising anode material for KIBs.

scholarly journals Evidence for a Solid-Electrolyte Inductive Effect in Superionic Conductors

2020 ◽  
Author(s):  
Sean Culver ◽  
Alex Squires ◽  
Nicolo Minafra ◽  
Callum Armstrong ◽  
Thorben Krauskopf ◽  
...  
Keyword(s):  
Solid Electrolyte ◽  
Solid Electrolytes ◽  
Density Functional ◽  
Inductive Effect ◽  
Ionic Conductivities ◽  
Lithium Ion ◽  
Density Functional Theory Calculations ◽  
Ion Diffusion ◽  
Functional Theory ◽  
Li Ion

<p>Identifying and optimizing highly-conducting lithium-ion solid electrolytes is a critical step towards the realization of commercial all–solid-state lithium-ion batteries. Strategies to enhance ionic conductivities in solid electrolytes typically focus on the effects of modifying their crystal structures or of tuning mobile-ion stoichiometries. A less-explored approach is to modulate the chemical-bonding interactions within a material to promote fast lithium-ion diffusion. Recently, the idea of a solid-electrolyte inductive effect was proposed, whereby changes in bonding within the solid-electrolyte host-framework modify the potential-energy landscape for the mobile ions, resulting in an enhanced ionic conductivity. This concept has since been invoked to explain anomalous conductivity trends in a number of solid electrolytes. Direct evidence for a solid-electrolyte inductive effect, however, is lacking—in part because of the challenge of quantifying changes in local bonding interactions within a solid-electrolyte host-framework. <a></a><a>Here, we consider the evidence for a solid-electrolyte inductive effect in the archetypal superionic lithium-ion conductor Li<sub>10</sub>Ge<sub>1−<i>x</i></sub>Sn<i><sub>x</sub></i>P<sub>2</sub>S<sub>12</sub>, using Rietveld refinements against high-resolution temperature-dependent neutron-diffraction data, Raman spectroscopy, and density functional theory calculations.</a> Substituting Ge for Sn weakens the {Ge,Sn}–S bonding interactions and increases the charge-density associated with the S<sup>2-</sup> ions. This charge redistribution modifies the Li<sup>+</sup> substructure causing Li<sup>+</sup> ions to bind more strongly to the host-framework S anions; which in turn modulates the Li-ion potential-energy surface, increasing local barriers for Li-ion diffusion. Each of these effects is consistent with the predictions of the solid-electrolyte inductive effect model. Density functional theory calculations further predict that this inductive effect occurs even in the absence of changes to the host-framework geometry due to Ge → Sn substitution. These results provide direct evidence in support of a measurable solid-electrolyte inductive effect and demonstrate its application as a practical strategy for tuning ionic conductivities in superionic lithium-ion conductors.</p>

scholarly journals Evidence for a Solid-Electrolyte Inductive Effect in Superionic Conductors

2020 ◽  
Author(s):  
Sean Culver ◽  
Alex Squires ◽  
Nicolo Minafra ◽  
Callum Armstrong ◽  
Thorben Krauskopf ◽  
...  
Keyword(s):  
Solid Electrolyte ◽  
Solid Electrolytes ◽  
Density Functional ◽  
Inductive Effect ◽  
Ionic Conductivities ◽  
Lithium Ion ◽  
Density Functional Theory Calculations ◽  
Ion Diffusion ◽  
Functional Theory ◽  
Li Ion

<p>Identifying and optimizing highly-conducting lithium-ion solid electrolytes is a critical step towards the realization of commercial all–solid-state lithium-ion batteries. Strategies to enhance ionic conductivities in solid electrolytes typically focus on the effects of modifying their crystal structures or of tuning mobile-ion stoichiometries. A less-explored approach is to modulate the chemical-bonding interactions within a material to promote fast lithium-ion diffusion. Recently, the idea of a solid-electrolyte inductive effect was proposed, whereby changes in bonding within the solid-electrolyte host-framework modify the potential-energy landscape for the mobile ions, resulting in an enhanced ionic conductivity. This concept has since been invoked to explain anomalous conductivity trends in a number of solid electrolytes. Direct evidence for a solid-electrolyte inductive effect, however, is lacking—in part because of the challenge of quantifying changes in local bonding interactions within a solid-electrolyte host-framework. <a></a><a>Here, we consider the evidence for a solid-electrolyte inductive effect in the archetypal superionic lithium-ion conductor Li<sub>10</sub>Ge<sub>1−<i>x</i></sub>Sn<i><sub>x</sub></i>P<sub>2</sub>S<sub>12</sub>, using Rietveld refinements against high-resolution temperature-dependent neutron-diffraction data, Raman spectroscopy, and density functional theory calculations.</a> Substituting Ge for Sn weakens the {Ge,Sn}–S bonding interactions and increases the charge-density associated with the S<sup>2-</sup> ions. This charge redistribution modifies the Li<sup>+</sup> substructure causing Li<sup>+</sup> ions to bind more strongly to the host-framework S anions; which in turn modulates the Li-ion potential-energy surface, increasing local barriers for Li-ion diffusion. Each of these effects is consistent with the predictions of the solid-electrolyte inductive effect model. Density functional theory calculations further predict that this inductive effect occurs even in the absence of changes to the host-framework geometry due to Ge → Sn substitution. These results provide direct evidence in support of a measurable solid-electrolyte inductive effect and demonstrate its application as a practical strategy for tuning ionic conductivities in superionic lithium-ion conductors.</p>

Bismuth germanate (Bi4Ge3O12), a promising high-capacity lithium-ion battery anode

2018 ◽  
Vol 54 (81) ◽  
pp. 11483-11486 ◽  
Author(s):  
Jassiel R. Rodriguez ◽  
Carlos Belman-Rodriguez ◽  
Sergio A. Aguila ◽  
Yanning Zhang ◽  
Hongxian Liu ◽  
...  
Keyword(s):  
Density Functional ◽  
High Capacity ◽  
Lithium Ion ◽  
Density Functional Theory Calculations ◽  
Reversible Capacity ◽  
Functional Theory ◽  
Tap Density ◽  
Micron Size ◽  
A Current ◽  
Battery Anode

Cubic Bi4Ge3O12 lithiation-host electrode material with micron size, low surface area (3 m2 g−1) and high tap density yielded a reversible capacity of 586 mA h g−1 at a current density of 200 mA g−1 after 500 charge–discharge cycles. Density functional theory calculations detected distorted [BiO6]9− octahedra with two types of Bi–O bonds.

MX (M = Ge, Sn; X = S, Se) sheets: theoretical prediction of new promising electrode materials for Li ion batteries

2016 ◽  
Vol 4 (28) ◽  
pp. 10906-10913 ◽  
Author(s):  
Yungang Zhou
Keyword(s):  
Density Functional Theory ◽  
High Performance ◽  
Density Functional ◽  
Electrode Materials ◽  
Lithium Ion ◽  
Density Functional Theory Calculations ◽  
Two Dimensional ◽  
Li Ion Batteries ◽  
Functional Theory ◽  
Li Ion

In this work, via density functional theory calculations, we explored the interaction of Li with recently synthesized two-dimensional structures, MX (M = Ge, Sn; X = S, Se) sheets, for application in high-performance lithium ion batteries.

Understanding the boosted sodium storage behavior of a nanoporous bismuth-nickel anode using operando X-ray diffraction and density functional theory calculations

2019 ◽  
Vol 7 (22) ◽  
pp. 13602-13613 ◽  
Author(s):  
Hui Gao ◽  
Lin Song ◽  
Jiazheng Niu ◽  
Chi Zhang ◽  
Tianyi Kou ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Storage Behavior ◽  
Atomic Substitution ◽  
Sodium Storage

A novel channel-enhanced strategy upon atomic substitution via a dealloying process for the improved Na storage of alloying-type anodes for SIBs.

Density functional theory calculations for the interaction of Li+ cations and PF6– anions with nonaqueous electrolytes

2011 ◽  
Vol 89 (12) ◽  
pp. 1525-1532 ◽  
Author(s):  
Mahesh Datt Bhatt ◽  
Maenghyo Cho ◽  
Kyeongjae Cho
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Ethylene Carbonate ◽  
Lithium Ion ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Nonaqueous Electrolytes ◽  
Ethyl Methyl ◽  
Methyl Carbonate ◽  
Solvent Molecules

The interaction of lithium (Li+) cation and hexafluorophosphate (PF6–) anion with nonaqueous electrolytes is studied by using density functional theory at the B3LYP/6–311++G(d,p) level in the gas phase in terms of the coordination of Li+ and PF6– with these solvents. Ethylene carbonate (EC) coordinates with Li+ and PF6– most strongly and reaches the anode and cathode most easily because of its highest dielectric constant among all the solvent molecules, resulting in its preferential reduction on the anode and oxidation on the cathode. For cyclic carbonates EC and propylene carbonate (PC), the structure Li+(S)4 is found to be the most stable. However, for linear carbonates dimethyl carbonate (DMC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC), the formation of PF6–(S)n=1–3 is not favorable. Such analysis may be useful in applications for lithium ion batteries.

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