scholarly journals Three-dimensional stable lithium metal anode with nanoscale lithium islands embedded in ionically conductive solid matrix

2017 ◽  
Vol 114 (18) ◽  
pp. 4613-4618 ◽  
Author(s):  
Dingchang Lin ◽  
Jie Zhao ◽  
Jie Sun ◽  
Hongbin Yao ◽  
Yayuan Liu ◽  
...  
Keyword(s):  
High Power ◽  
Power Output ◽  
Three Dimensional ◽  
Rechargeable Batteries ◽  
Solid Matrix ◽  
Side Reactions ◽  
Surface Protection ◽  
Metal Anode ◽  
Practical Applications ◽  
Significant Step

Rechargeable batteries based on lithium (Li) metal chemistry are attractive for next-generation electrochemical energy storage. Nevertheless, excessive dendrite growth, infinite relative dimension change, severe side reactions, and limited power output severely impede their practical applications. Although exciting progress has been made to solve parts of the above issues, a versatile solution is still absent. Here, a Li-ion conductive framework was developed as a stable “host” and efficient surface protection to address the multifaceted problems, which is a significant step forward compared with previous host concepts. This was fulfilled by reacting overstoichiometry of Li with SiO. The as-formed LixSi–Li2O matrix would not only enable constant electrode-level volume, but also protect the embedded Li from direct exposure to electrolyte. Because uniform Li nucleation and deposition can be fulfilled owing to the high-density active Li domains, the as-obtained nanocomposite electrode exhibits low polarization, stable cycling, and high-power output (up to 10 mA/cm2) even in carbonate electrolytes. The Li–S prototype cells further exhibited highly improved capacity retention under high-power operation (∼600 mAh/g at 6.69 mA/cm2). The all-around improvement on electrochemical performance sheds light on the effectiveness of the design principle for developing safe and stable Li metal anodes.

scholarly journals Lithiophilicity chemistry of heteroatom-doped carbon to guide uniform lithium nucleation in lithium metal anodes

2019 ◽  
Vol 5 (2) ◽  
pp. eaau7728 ◽  
Author(s):  
Xiang Chen ◽  
Xiao-Ru Chen ◽  
Ting-Zheng Hou ◽  
Bo-Quan Li ◽  
Xin-Bing Cheng ◽  
...  
Keyword(s):  
First Principles ◽  
Rechargeable Batteries ◽  
First Principles Calculations ◽  
Composite Anode ◽  
Metal Anode ◽  
Practical Applications ◽  
Nucleation Overpotential ◽  
Lithium Metal Anodes ◽  
Li Metal Anode ◽  
Co Doped

The uncontrollable growth of lithium (Li) dendrites seriously impedes practical applications of Li metal batteries. Various lithiophilic conductive frameworks, especially carbon hosts, are used to guide uniform Li nucleation and thus deliver a dendrite-free composite anode. However, the lithiophilic nature of these carbon hosts is poorly understood. Herein, the lithiophilicity chemistry of heteroatom-doped carbon is investigated through both first principles calculations and experimental verifications to guide uniform Li nucleation. The electronegativity, local dipole, and charge transfer are proposed to reveal the lithiophilicity of doping sites. Li bond chemistry further deepens the understanding of lithiophilicity. The O-doped and O/B–co-doped carbons exhibit the best lithiophilicity among single-doped and co-doped carbons, respectively. The excellent lithiophilicity achieved by O-doping carbon is further validated by Li nucleation overpotential measurement. This work uncovers the lithiophilicity chemistry of heteroatom-doped carbons and affords a mechanistic guidance to Li metal anode frameworks for safe rechargeable batteries.

scholarly journals Remedies to Avoid Failure Mechanisms of Lithium-Metal Anode in Li-Ion Batteries

Inorganics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 5
Author(s):  
Alain Mauger ◽  
Christian M. Julien
Keyword(s):  
Failure Modes ◽  
Solid Electrolyte Interphase ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Ex Situ ◽  
Side Reactions ◽  
Lithium Metal ◽  
Metal Anode ◽  
Lithium Metal Anode ◽  
Power And Energy

Rechargeable lithium-metal batteries (LMBs), which have high power and energy density, are very attractive to solve the intermittence problem of the energy supplied either by wind mills or solar plants or to power electric vehicles. However, two failure modes limit the commercial use of LMBs, i.e., dendrite growth at the surface of Li metal and side reactions with the electrolyte. Substantial research is being accomplished to mitigate these drawbacks. This article reviews the different strategies for fabricating safe LMBs, aiming to outperform lithium-ion batteries (LIBs). They include modification of the electrolyte (salt and solvents) to obtain a highly conductive solid–electrolyte interphase (SEI) layer, protection of the Li anode by in situ and ex situ coatings, use of three-dimensional porous skeletons, and anchoring Li on 3D current collectors.

scholarly journals Cross-linked beta alumina nanowires with compact gel polymer electrolyte coating for ultra-stable sodium metal battery

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Danni Lei ◽  
Yan-Bing He ◽  
Huijuan Huang ◽  
Yifei Yuan ◽  
Guiming Zhong ◽  
...  
Keyword(s):  
Polymer Electrolyte ◽  
Vinylidene Fluoride ◽  
Gel Polymer Electrolyte ◽  
High Energy ◽  
Side Reactions ◽  
Composite Electrolyte ◽  
Metal Anode ◽  
Practical Applications ◽  
Sodium Metal ◽  
Beta Alumina

Abstract Sodium metal batteries have potentially high energy densities, but severe sodium-dendrite growth and side reactions prevent their practical applications, especially at high temperatures. Herein, we design an inorganic ionic conductor/gel polymer electrolyte composite, where uniformly cross-linked beta alumina nanowires are compactly coated by a poly(vinylidene fluoride-co-hexafluoropropylene)-based gel polymer electrolyte through their strong molecular interactions. These  beta alumina nanowires combined with the gel polymer layer create dense and homogeneous solid-liquid hybrid sodium-ion transportation channels through and along the nanowires, which promote uniform sodium deposition and formation of a stable and flat solid electrolyte interface on the sodium metal anode. Side reactions between the sodium metal and liquid electrolyte, as well as sodium dendrite formation, are successfully suppressed, especially at 60 °C. The sodium vanadium phosphate/sodium full cells with composite electrolyte exhibit 95.3% and 78.8% capacity retention after 1000 cycles at 1 C at 25 °C and 60 °C, respectively.

scholarly journals Supercritical CO2 Synthesis of Freestanding Se1-xSx Foamy Cathodes for High-Performance Li-Se1-xSx Battery

2021 ◽  
Vol 9 ◽  
Author(s):  
Chengwei Lu ◽  
Ruyi Fang ◽  
Kun Wang ◽  
Zhen Xiao ◽  
G. Gnana kumar ◽  
...  
Keyword(s):  
High Performance ◽  
Specific Capacity ◽  
Three Dimensional ◽  
Rate Capability ◽  
Carbon Matrix ◽  
High Energy ◽  
Rechargeable Batteries ◽  
High Energy Density ◽  
Rechargeable Lithium Batteries ◽  
Practical Applications

Selenium-sulfur solid solutions (Se1-xSx) are considered to be a new class of promising cathodic materials for high-performance rechargeable lithium batteries owing to their superior electric conductivity than S and higher theoretical specific capacity than Se. In this work, high-performance Li-Se1-xSx batteries employed freestanding cathodes by encapsulating Se1-xSx in a N-doped carbon framework with three-dimensional (3D) interconnected porous structure (NC@SWCNTs) are proposed. Se1-xSx is uniformly dispersed in 3D porous carbon matrix with the assistance of supercritical CO2 (SC-CO2) technique. Impressively, NC@SWCNTs host not only provides spatial confinement for Se1-xSx and efficient physical/chemical adsorption of intermediates, but also offers a highly conductive framework to facilitate ion/electron transport. More importantly, the Se/S ratio of Se1-xSx plays an important role on the electrochemical performance of Li- Se1-xSx batteries. Benefiting from the rationally designed structure and chemical composition, NC@[email protected] cathode exhibits excellent cyclic stability (632 mA h g−1 at 200 cycle at 0.2 A g−1) and superior rate capability (415 mA h g−1 at 2.0 A g−1) in carbonate-based electrolyte. This novel NC@[email protected] cathode not only introduces a new strategy to design high-performance cathodes, but also provides a new approach to fabricate freestanding cathodes towards practical applications of high-energy-density rechargeable batteries.

scholarly journals Lithium Metal Anode Materials Design: Interphase and Host

2019 ◽  
Vol 2 (4) ◽  
pp. 509-517 ◽  
Author(s):  
Hansen Wang ◽  
Yayuan Liu ◽  
Yuzhang Li ◽  
Yi Cui
Keyword(s):  
High Performance ◽  
Coulombic Efficiency ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Metal Anode ◽  
Practical Applications ◽  
Nanoscale Characterization ◽  
Long Time ◽  
Li Metal Anode

Abstract Li metal is the ultimate anode choice due to its highest theoretical capacity and lowest electrode potential, but it is far from practical applications with its poor cycle lifetime. Recent research progresses show that materials designs of interphase and host structures for Li metal are two effective ways addressing the key issues of Li metal anodes. Despite the exciting improvement on Li metal cycling capability, problems still exist with these methodologies, such as the deficient long-time cycling stability of interphase materials and the accelerated Li corrosion for high surface area three-dimensional composite Li anodes. As a result, Coulombic efficiency of Li metal is still not sufficient for full-cell cycling. In the near future, an interphase protected three-dimensional composite Li metal anode, combined with high performance novel electrolytes might be the ultimate solution. Besides, nanoscale characterization technologies are also vital for guiding future Li metal anode designs. Graphic Abstract

scholarly journals Homogeneous guiding deposition of sodium through main group II metals toward dendrite-free sodium anodes

2019 ◽  
Vol 5 (4) ◽  
pp. eaau6264 ◽  
Author(s):  
Mengqi Zhu ◽  
Songmei Li ◽  
Bin Li ◽  
Yongji Gong ◽  
Zhiguo Du ◽  
...  
Keyword(s):  
Low Cost ◽  
Metal Organic Framework ◽  
Specific Capacity ◽  
Three Dimensional ◽  
Main Group ◽  
Metallic Sodium ◽  
Metal Anode ◽  
Practical Applications ◽  
Metal Organic ◽  
Group Ii

Metallic sodium is a potential anode material for rechargeable sodium-based batteries because of its high specific capacity and low cost. However, sodium commonly suffers from severe sodium dendrites and infinitely huge volume change, hampering its practical applications. Here, we demonstrate that sodium can be controllably deposited through main group II metals such as Be, Mg, and Ba since they have definite solubility in sodium and thus enable a marked reduction of the nucleation barriers of sodium, guiding the parallel growth of sodium on the metal substrates. By further homogeneously dispersing Mg clusters in a three-dimensional hierarchical structure on the basis of a carbonized Mg-based metal-organic framework–74 membrane, the nucleation barriers of sodium can be eliminated, owing to the plentiful Mg nucleation seeds. Hence, a dendrite-free sodium metal anode with a very low overpotential of 27 mV and a superior cycling stability of up to 1350 hours is achieved.

scholarly journals An ion redistributor for dendrite-free lithium metal anodes

2018 ◽  
Vol 4 (11) ◽  
pp. eaat3446 ◽  
Author(s):  
Chen-Zi Zhao ◽  
Peng-Yu Chen ◽  
Rui Zhang ◽  
Xiang Chen ◽  
Bo-Quan Li ◽  
...  
Keyword(s):  
Coulombic Efficiency ◽  
Specific Capacity ◽  
Three Dimensional ◽  
Rechargeable Batteries ◽  
Ion Concentration ◽  
Universal Method ◽  
Ion Distribution ◽  
Practical Applications ◽  
Li Ion ◽  
Metal Anodes

Lithium (Li) metal anodes have attracted considerable interest due to their ultrahigh theoretical gravimetric capacity and very low redox potential. However, the issues of nonuniform lithium deposits (dendritic Li) during cycling are hindering the practical applications of Li metal batteries. Herein, we propose a concept of ion redistributors to eliminate dendrites by redistributing Li ions with Al-doped Li6.75La3Zr1.75Ta0.25O12 (LLZTO) coated polypropylene (PP) separators. The LLZTO with three-dimensional ion channels can act as a redistributor to regulate the movement of Li ions, delivering a uniform Li ion distribution for dendrite-free Li deposition. The standard deviation of ion concentration beneath the LLZTO composite separator is 13 times less than that beneath the routine PP separator. A Coulombic efficiency larger than 98% over 450 cycles is achieved in a Li | Cu cell with the LLZTO-coated separator. This approach enables a high specific capacity of 140 mAh g−1 for LiFePO4 | Li pouch cells and prolonged cycle life span of 800 hours for Li | Li pouch cells, respectively. This strategy is facile and efficient in regulating Li-ion deposition by separator modifications and is a universal method to protect alkali metal anodes in rechargeable batteries.

Mechanical Aspects of the Sprint Start in Olympic Speed Skating

1989 ◽  
Vol 5 (2) ◽  
pp. 151-168 ◽  
Author(s):  
Jos J. de Koning ◽  
Gert de Groot ◽  
Gerrit Jan van Ingen Schenau
Keyword(s):  
High Power ◽  
Power Output ◽  
Mechanical Characteristics ◽  
Olympic Games ◽  
Three Dimensional ◽  
Film Analysis ◽  
Male And Female ◽  
Speed Skating ◽  
High Power Output ◽  
Winter Olympic Games

Mechanical characteristics of the sprint start in speed skating were measured during the 1988 Winter Olympic Games. From three-dimensional film analysis of the first 4 seconds of the male and female 500-m races, biomechanical variables were determined. The first strokes during the start appeared to be performed by a running-like technique. At a forward velocity of approximately 4 m/sec, the skaters are forced to change this technique to the typical gliding technique as used during speed skating at steady speed. In explaining the time differences on the first 100 meters of the 500-m speed skating race, the effectiveness of the push-off appears to be more important than the observed high power output levels.

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