scholarly journals Improving the stability, lithium diffusion dynamics, and specific capacity of SrLi2Ti6O14 via ZrO2 coating

2020 ◽  
Author(s):  
Hong-Li Ding ◽  
Hai-Tao Yu ◽  
Xiao-dong Wang ◽  
Chen-Feng Guo ◽  
Bing Zheng ◽  
...  
Keyword(s):  
Specific Capacity ◽  
Zro2 Coating ◽  
Diffusion Dynamics ◽  
Lithium Diffusion ◽  
The Stability

Synthesis of Bi2S3/MoS2 Nanorods and Their Enhanced Electrochemical Performance for Aluminum Ion Batteries

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
Shimeng Zhao ◽  
Jialin Li ◽  
Haixia Chen ◽  
Jianxin Zhang
Keyword(s):  
Cathode Materials ◽  
High Performance ◽  
Low Cost ◽  
Specific Capacity ◽  
Discharge Voltage ◽  
Aluminum Ion ◽  
High Charge Density ◽  
Initial Charge ◽  
New Type ◽  
The Stability

Abstract Rechargeable aluminum ion batteries (AIBs) have attracted much attention because of their high charge density, low cost, and low flammability. Transition metal sulfides are a class of cathode materials that have been extensively studied. In this report, Bi2S3 nanorods and Bi2S3/MoS2 nanorods were synthesized by the hydrothermal method as new type of cathode materials for rechargeable AIBs. The diameter of Bi2S3/MoS2 nanorods is 20–100 nm. The Bi2S3 nanorods display high initial charge and discharge capacities of 343.3 and 251 mA h/g with a current density of 1 A/g. The static cycling for the Bi2S3/MoS2 nanorods electrode at 1 A/g denotes high stability with a specific capacity of 132.9 mA h/g after 100 cycles. The charging voltage platform of Bi2S3 nanorods and Bi2S3/MoS2 nanorods is at 1.1–1.4 V, and the discharge voltage platform is at around 0.8 V. The well-defined heterojunction maintains the stability of the Bi2S3 structure during long-term cycling, which is desirable for aluminum ion batteries. This strategy reveals new insights for designing cathode materials of high-performance AIBs.

Oxygen containing Si–H nanoparticles: a potential electrode for Li–ion battery

2018 ◽  
Vol 83 (1) ◽  
pp. 10401
Author(s):  
Priya Francis ◽  
Subhash V Ghaisas
Keyword(s):  
Density Functional ◽  
Specific Capacity ◽  
Nano Particles ◽  
Functional Theory ◽  
Intercalation Process ◽  
Potential Electrode ◽  
Li Ion ◽  
The Stability ◽  
Structure Calculations

Using density functional theory based computations; the role of vacancy and defects in hydrogen terminated silicon nano particles (NP) in the lithium intercalation process is investigated. The study shows that Li cannot bind to the NPs without vacancy or defects. The presence of a single dangling bond or defects such as O or OH radical substituting H, induces interaction between Li atoms and NPs. The Si–Si coordination number reduces with increasing Li intake however, total average coordination of Si increases beyond 5. Presence of H, O and OH is seen to be conducive for the intercalation process. The average electrode potential with respect to Li/Li+ is seen to vary between 2.4 and 0.05 V over NPs with various defects. It is observed that one of the stable electrode material can be Si10H8O4 NPs. Electronic structure calculations of the intercalation of up to13 Li in Si10H8O4 NPs was carried out. It corresponds to a specific capacity of 988 mAh g−1 for these NPs. The results can be extrapolated for higher intake, making this material a potential anode. The stability analysis shows that Si:H NPs containing oxygen are stable and are promising material for anode in lithium battery under deep discharge.

First-principles study of the stability of silicane and germanane under strain

2014 ◽  
Vol 28 (17) ◽  
pp. 1450138 ◽  
Author(s):  
T. Y. Du ◽  
J. Zhao ◽  
G. Liu ◽  
J. X. Le ◽  
B. Xu
Keyword(s):  
First Principles ◽  
Lattice Dynamics ◽  
Density Functional ◽  
Tensile Strain ◽  
Helmholtz Free Energy ◽  
Compressive Strain ◽  
Specific Capacity ◽  
Biaxial Strain ◽  
Functional Theory ◽  
The Stability

In this paper, we investigate the structural stability of silicane and germanane under biaxial strain by employing the lattice dynamics calculations within the frame of density functional theory. Our results show that silicane and germanane become unstable even under 1% compressive strain, while maintaining stable under tensile strain. Further calculations about the thermodynamical properties of silicane and germanane show that the phonon contribution to Helmholtz free energy, entropy and specific capacity are insensitive to the tensile strain.

scholarly journals A Non-Flammable Zwitterionic Ionic Liquid/Ethylene Carbonate Mixed Electrolyte for Lithium-Ion Battery with Enhanced Safety

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4225
Author(s):  
Zeliang Guan ◽  
Zhijun Zhang ◽  
Binyang Du ◽  
Zhangquan Peng
Keyword(s):  
Ionic Liquid ◽  
Ionic Conductivity ◽  
Safety Issue ◽  
Ethylene Carbonate ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Mixed Electrolyte ◽  
The Stability ◽  
Reliable Solution

Today, the requirement for clean, highly efficient, and safe energy seems to be higher and higher due to non-renewable energy and pollution of the environment. At this moment, lithium-ion batteries (LIBs) look like a reliable solution for this dilemma since they have huge energy density. However, the flammability of the conventional electrolyte used in the LIBs is one of critical disadvantages of LIBs, which compromises the safety issue of LIBs. Herein, we reported a non-flammable zwitterionic ionic liquid-based electrolyte named TLPEC, which was fabricated by simply mixing a novel zwitterionic ionic liquid TLP (93 wt%) and ethylene carbonate (EC, 7 wt%). The TLPEC electrolyte exhibited a wide electrochemical potential window of 1.65–5.10 V and a robust ionic conductivity of 1.0 × 10−3 S cm−1 at 20 °C, which renders TLPEC to be a suitable electrolyte for LIBs with enhanced safety performance. The LIBs, with TLPEC as the electrolyte, exhibited an excellent performance in terms of excellent rate capability, cycling stability, and high specific capacity at 25 and 60 °C, which were attributed to the stability and high ionic conductivity of TLPEC electrolyte during cycling as well as the excellent interface compatibility of TLPEC electrolyte with lithium anode.

scholarly journals Phase transitions and stability of dynamical processes on hypergraphs

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Guilherme Ferraz de Arruda ◽  
Michele Tizzani ◽  
Yamir Moreno
Keyword(s):  
Diffusion Processes ◽  
Weighted Graph ◽  
Social Contagion ◽  
General Interest ◽  
Dynamical Processes ◽  
Natural Systems ◽  
Pairwise Interactions ◽  
Diffusion Dynamics ◽  
Stability Of Dynamical Systems ◽  
The Stability

AbstractHypergraphs naturally represent higher-order interactions, which persistently appear in social interactions, neural networks, and other natural systems. Although their importance is well recognized, a theoretical framework to describe general dynamical processes on hypergraphs is not available yet. In this paper, we derive expressions for the stability of dynamical systems defined on an arbitrary hypergraph. The framework allows us to reveal that, near the fixed point, the relevant structure is a weighted graph-projection of the hypergraph and that it is possible to identify the role of each structural order for a given process. We analytically solve two dynamics of general interest, namely, social contagion and diffusion processes, and show that the stability conditions can be decoupled in structural and dynamical components. Our results show that in social contagion process, only pairwise interactions play a role in the stability of the absorbing state, while for the diffusion dynamics, the order of the interactions plays a differential role. Our work provides a general framework for further exploration of dynamical processes on hypergraphs.

Effect of Fluorine-Containing Additive on the Electrochemical Properties of Silicon Anode for Lithium-Ion Batteries

2019 ◽  
Vol 944 ◽  
pp. 699-704 ◽  
Author(s):  
Jing Wang ◽  
Xiao Hang Yang ◽  
Yue Feng Su ◽  
Shi Chen ◽  
Feng Wu
Keyword(s):  
Lithium Ion Batteries ◽  
Coulombic Efficiency ◽  
Solid Electrolyte Interphase ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Silicon Anode ◽  
Cycle Stability ◽  
Promising Candidate ◽  
Sem Images ◽  
The Stability

Silicon anode is a promising candidate as an alternative to the conventional graphitic anode in lithium-ion batteries. In this work, silicon anode is modified by NH4F using a facile method in air. The concentration of NH4F on the electrochemical performance is systematically checked. The 5wt%NH4F-modified silicon anode exhibits enhanced cycle and rate performances, the first discharge specific capacity is 3958 mAh·g-1 with 86.45% as the coulombic efficiency at 0.4A·g-1. The capacity can maintain at 703.3 mAh·g-1 after 50 cycles, exhibiting a much better cycle stability than pristine silicon anode (329.9 mAh·g-1 after 50 cycles). SEM images confirm that NH4F can alleviate the volume expansion of silicon since LiF can be generated at the surface which is beneficial to the stability of solid-electrolyte interphase (SEI).

scholarly journals High-Defect-Density Graphite for Superior-Performance Aluminum-Ion Batteries with Ultra-Fast Charging and Stable Long Life

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jisu Kim ◽  
Michael Ruby Raj ◽  
Gibaek Lee
Keyword(s):  
Cathode Materials ◽  
Carbon Materials ◽  
Defect Density ◽  
Specific Capacity ◽  
High Energy ◽  
Graphitic Carbon ◽  
Superior Performance ◽  
Aluminum Ion ◽  
Diffusion Dynamics ◽  
Long Life

AbstractRechargeable aluminum-ion batteries (AIBs) are a new generation of low-cost and large-scale electrical energy storage systems. However, AIBs suffer from a lack of reliable cathode materials with insufficient intercalation sites, poor ion-conducting channels, and poor diffusion dynamics of large chloroaluminate anions (AlCl4− and Al2Cl7−). To address these issues, surface-modified graphitic carbon materials [i.e., acid-treated expanded graphite (AEG) and base-etched graphite (BEG)] are developed as novel cathode materials for ultra-fast chargeable AIBs. AEG has more turbostratically ordered structure covered with abundant micro- to nano-sized pores on the surface structure and expanded interlayer distance (d002 = 0.3371 nm) realized by surface treatment of pristine graphite with acidic media, which can be accelerated the diffusion dynamics and efficient AlCl4− ions (de)-intercalation kinetics. The AIB system employing AEG exhibits a specific capacity of 88.6 mAh g−1 (4 A g−1) and ~ 80 mAh g−1 at an ultra-high current rate of 10 A g−1 (~ 99.1% over 10,000 cycles). BEG treated with KOH solution possesses the turbostratically disordered structure with high density of defective sites and largely expanded d-spacing (d002 = 0.3384 nm) for attracting and uptaking more AlCl4− ions with relatively shorter penetration depth. Impressively, the AIB system based on the BEG cathode delivers a high specific capacity of 110 mAh g−1 (4 A g−1) and ~ 91 mAh g−1 (~ 99.9% over 10,000 cycles at 10 A g−1). Moreover, the BEG cell has high energy and power densities of 247 Wh kg−1 and 44.5 kW kg−1. This performance is one of the best among the AIB graphitic carbon materials reported for chloroaluminate anions storage performance. This finding provides great significance for the further development of rechargeable AIBs with high energy, high power density, and exceptionally long life.

Design of functional nanocomposites based on graphene and graphene-like materials, as well as organic conjugated polymers – promising electrode materials for supercapacitors and heterogeneous catalysts

2021 ◽  
pp. 11-25
Author(s):  
Yaroslav I. Kurys ◽  
◽  
Olha A. Kozarenko ◽  
Vyacheslav G. Koshechko ◽  
Vitaly D. Pokhodenko ◽  
...  
Keyword(s):  
Specific Energy ◽  
Heterogeneous Catalysts ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Ammonium Persulfate ◽  
Hydrogenation Reaction ◽  
Specific Power ◽  
Active Electrode ◽  
The Stability ◽  
Charge Discharge

The results obtained during the project on the development of promising functional nanocomposites based on graphene and graphene-like materials, as well as conducting polymers as active electrode materials for symmetric supercapacitors (SSC) and heterogeneous catalysts for quinoline hydrogenation are considered. Using a mechanochemical approach, nanocomposites based on polyaniline (PAni) and a number of 2D materials (nanostructured graphite – nG, molybdenum disulfide – nMoS2, tungsten disulfide – nWS2) were obtained. It was found that PAni/nG-based electrodes are able to provide the specific capacity of ~360 F/g in SSC and stability for at least 10,000 charge-discharge cycles. It is shown that PAni/nG-based SSC is able to operate at high current and the specific power of SSC can reach ~10 kW/kg at the specific energy of ~18 W∙h/kg. In the study of SSC based on nMoS2/PAni and nWS2/PAni, it was found that nanoparticles of d-metal sulfides to promote electrochemical reversibility of redox conversion in PAni at high potentials and contribute to the stability of nanocomposites during prolonged charge-discharge cycling. The specific capacity of such materials can reach 610 F/g and the specific power of SSC can reach ~4.1 kW/kg for specific energy ~23.5 W·h/kg. A number of Co-containing nanocomposites consisting of Co9S8 particles on Co,N,S-doped carbon was obtained by pyrolysis using various nanosized carbon materials and the monomer (5-aminoindole) - oxidant (ammonium persulfate) system. High catalytic activity of the obtained nanocomposites in the quinoline hydrogenation reaction was demonstrated – the yield of the target product (1,2,3,4-tetrahydroquinoline) is from ~85-90% to almost quantitative.

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