scholarly journals Formation of lithiated gold and its use for the preparation of reference electrodes — an EQCM study

Author(s):  
Christopher Behling ◽  
Karl J. J. Mayrhofer ◽  
Balázs B. Berkes

AbstractLithiated gold wires can be used to build reference electrodes with outstanding potential stabilities over several days and even over the course of one year. These electrodes are well suited for investigations in the context of lithium-ion batteries (LIBs). In this work, a detailed procedure for the preparation of such electrodes with tailored mechanical properties, which can be fitted gastight into electrochemical cells using commercially available fittings, is given. The electrochemical lithiation process is studied using the electrochemical quartz crystal microbalance (EQCM) technique, and the differences in lithiation of wire type and thin film type gold electrodes are discussed. All experiments were carried out with two different electrolytes, namely, a LiPF6 and a lithium bis(trifluoromethane sulfonyl) imide (LiTFSI)-based electrolyte, and we conclude that for a higher lithiation rate and long-term stability, the use of LiTFSI-based electrolyte in the preparation phase is beneficial. The EQCM data provides a better insight in the analysis of film formation processes, like the buildup of the solid electrolyte interphase (SEI) during the lithiation, the rate of deposition of metallic lithium, or additional information on the kinetics of Li-Au alloy formation.

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Rajesh Pathak ◽  
Ke Chen ◽  
Ashim Gurung ◽  
Khan Mamun Reza ◽  
Behzad Bahrami ◽  
...  

AbstractLithium metal anodes have attracted extensive attention owing to their high theoretical specific capacity. However, the notorious reactivity of lithium prevents their practical applications, as evidenced by the undesired lithium dendrite growth and unstable solid electrolyte interphase formation. Here, we develop a facile, cost-effective and one-step approach to create an artificial lithium metal/electrolyte interphase by treating the lithium anode with a tin-containing electrolyte. As a result, an artificial solid electrolyte interphase composed of lithium fluoride, tin, and the tin-lithium alloy is formed, which not only ensures fast lithium-ion diffusion and suppresses lithium dendrite growth but also brings a synergistic effect of storing lithium via a reversible tin-lithium alloy formation and enabling lithium plating underneath it. With such an artificial solid electrolyte interphase, lithium symmetrical cells show outstanding plating/stripping cycles, and the full cell exhibits remarkably better cycling stability and capacity retention as well as capacity utilization at high rates compared to bare lithium.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Srivatsan Ramesh ◽  
K. Venkata Ratnam ◽  
Balaji Krishnamurthy

A one-dimensional model based on solvent diffusion and kinetics to study the formation of the SEI (solid electrolyte interphase) layer and its impact on the capacity of a lithium ion battery is developed. The model uses the earlier work on silicon oxidation but studies the kinetic limitations of the SEI growth process. The rate constant of the SEI formation reaction at the anode is seen to play a major role in film formation. The kinetics of the reactions for capacity fading for various battery systems are studied and the rate constants are evaluated. The model is used to fit the capacity fade in different battery systems.


2020 ◽  
Author(s):  
Paul Kitz ◽  
Matthew Lacey ◽  
Petr Novák ◽  
Erik Berg

<div>The electrolyte additives vinylene carbonate (VC) and fluoroethylene carbonate (FEC) are well known for increasing the lifetime of a Li-ion battery cell by supporting the formation of an effective solid electrolyte interphase (SEI) at the anode. In this study combined simultaneous electrochemical impedance spectroscopy (EIS) and <i>operando</i> electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) are employed together with <i>in situ</i> gas analysis (OEMS) to study the influence of VC and FEC on the passivation process and the interphase properties at carbon-based anodes. In small quantities both additives reduce the initial interphase mass loading by 30 to 50 %, but only VC also effectively prevents continuous side reactions and improves anode passivation significantly. VC and FEC are both reduced at potentials above 1 V vs. Li<sup>+</sup>/Li in the first cycle and change the SEI composition which causes an increase of the SEI shear storage modulus by over one order of magnitude in both cases. As a consequence, the ion diffusion coefficient and conductivity in the interphase is also significantly affected. While small quantities of VC in the initial electrolyte increase the SEI conductivity, FEC decomposition products hinder charge transport through the SEI and thus increase overall anode impedance significantly. </div>


2021 ◽  
Vol 370 ◽  
pp. 137777
Author(s):  
Andrew M. Colclasure ◽  
Xuemin Li ◽  
Lei Cao ◽  
Donal P. Finegan ◽  
Chuanbo Yang ◽  
...  

Physchem ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 26-44
Author(s):  
Chiara Ferrara ◽  
Riccardo Ruffo ◽  
Piercarlo Mustarelli

Extended interphases are playing an increasingly important role in electrochemical energy storage devices and, in particular, in lithium-ion and lithium metal batteries. With this in mind we initially address the differences between the concepts of interface and interphase. After that, we discuss in detail the mechanisms of solid electrolyte interphase (SEI) formation in Li-ion batteries. Then, we analyze the methods for interphase characterization, with emphasis put on in-situ and operando approaches. Finally, we look at the near future by addressing the issues underlying the lithium metal/electrolyte interface, and the emerging role played by the cathode electrolyte interphase when high voltage materials are employed.


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