Degradation mechanisms of lithium sulfide (Li2S) composite cathode in carbonate electrolyte and improvement by increasing electrolyte concentration

2021 ◽  
Vol 5 (6) ◽  
pp. 1714-1726
Author(s):  
Hidehisa Mokudai ◽  
Tomonari Takeuchi ◽  
Hikari Sakaebe ◽  
Hironori Kobayashi ◽  
Eiichiro Matsubara
Keyword(s):  
Electrolyte Concentration ◽  
Composite Cathode ◽  
Degradation Mechanisms ◽  
Lithium Sulfide ◽  
Organic Polysulfides

Lithium polysulfides (Li2Sn) react with carbonate solvents, forming organic polysulfides (R–Sn–R) and sulfides (R–S–R); the concentrated electrolyte suppresses these reactions.

Symmetric Lithium Sulfide – Sulfur Cells: A Method to Study Degradation Mechanisms of Cathode, Separator and Electrolyte Concepts for Lithium-Sulfur Batteries

2018 ◽  
Vol 165 (5) ◽  
pp. A1084-A1091 ◽  
Author(s):  
Markus Piwko ◽  
Christine Weller ◽  
Felix Hippauf ◽  
Susanne Dörfler ◽  
Holger Althues ◽  
...  
Keyword(s):  
Degradation Mechanisms ◽  
Sulfide Sulfur ◽  
Lithium Sulfide ◽  
Lithium Sulfur Batteries ◽  
Lithium Sulfur

Electrochemical Degradation of Phenol by the Nanographite and Foam-Ni Composite Cathode

2013 ◽  
Vol 664 ◽  
pp. 458-462 ◽  
Author(s):  
Xiu Juan Yu ◽  
Tian Yi Sun
Keyword(s):  
Degradation Rate ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Composite Cathode ◽  
Electrochemical Degradation ◽  
Initial Ph ◽  
Aeration Conditions ◽  
Diaphragm Cell ◽  
Activity Decrease ◽  
Electrolysis System

The degradation of phenol was demonstrate with a novel two-layer type cathode (TTC). For the fabrication of TTC, chitosan was firstly deposited on foam nickel, then one piece of the resulting foam-Ni film and one piece of nanographite(Nano-G) composite film were fasten to obtain the two-layer type nano-G︱foam-Ni cathode. The electrolysis phenol was conducted by self-made cathode and the Ti/IrO2/RuO2 anode in the diaphragm cell. The results showed that in the diaphragm electrolysis system with the aeration conditions, the degradation rate of phenol reached 97.15% under 120min’s electrolysis, when current density was 39 mA/cm2, initial pH value was 12 and electrolyte concentration was 0.1 mol/L. This two-layer type cathode could be reused without catalytic activity decrease, suggesting its potential application in the wastewater treatment.

Study on the influence on the formation of highly ordered porous anodic aluminia membrane

2017 ◽  
Author(s):  
O Pong-Sik ◽  
Ryang Se-Hun ◽  
Sin Gum-Chol ◽  
Hwang Guk-Nam ◽  
yongson hong
Keyword(s):  
Pore Diameter ◽  
Electrolyte Concentration ◽  
Aao Template ◽  
Alumina Template ◽  
Wide Range ◽  
Electrochemical Mechanism ◽  
Porous Anodic Alumina Template ◽  
Ordered Porous ◽  
Anodic Alumina Template ◽  
Scanning Electron

We have studied porous anodic alumina template through the second anodic oxidation of preparation. Observing the morphology of nanoscale AAO template using scanning electron microscope (SEM), the results indicate that the pores are orderly paralleled arranged with uniform pore diameter, perpendicular to the template surface. A detailed study of the influence of different oxidation conditions, such as different type of electrolyte, concentration, voltage and temperature on the template of alumina and its electrochemical mechanism were performed. By changing the oxidation voltage, electrolyte type, concentration, pore diameter and template thickness can be altered in a wide range such that we can obtain the desired aspect ratio. <br>

Chemical Transformation of Fe, Air & Water to Ammonia: Variation of Reaction Rate with Temperature, Pressure, Alkalinity and Iron

2018 ◽  
Author(s):  
Ping Peng ◽  
Fang-Fang Li ◽  
Xinye Liu ◽  
Jiawen Ren ◽  
jessica stuart ◽  
...  
Keyword(s):  
Particle Size ◽  
Reaction Rate ◽  
Electrolyte Concentration ◽  
Iron Concentration ◽  
Reaction Medium ◽  
Iron Particle ◽  
Intermediate Step ◽  
Ammonia Production ◽  
Pure Nitrogen ◽  
Alkaline Reaction

The rate of ammonia production by the <u>chemical </u>oxidation of iron, N<sub>2</sub>(from air or as pure nitrogen) and water is studied as a function of (1) iron particle size, (2) iron concentration, (3) temperature, (4) pressureand (5) concentration of the alkaline reaction medium. The reaction meduium consists of an aqueous solution of equal molal concentrations of NaOH and KOH (Na<sub>0.5</sub>K<sub>0.5</sub>OH). We had previously reported on the <u>chemical </u>reaction of iron and nitrogen in alkaline medium to ammonia as an intermediate step in the <u>electrochemical </u>synthesis of ammonia by a nano-sized iron oxide electrocatlyst. Here, the intermediate <u>chemical </u>reaction step is exclusively explored. The ammonia production rate increases with temperature (from 20 to 250°C), pressure (from 1 atm to 15 atm of air or N<sub>2</sub>), and exhibits a maximum rate at an electrolyte concentration of 8 molal Na<sub>0,5</sub>K<sub>0,5</sub>OH in a sealed N<sub>2</sub>reactor. 1-3 µm particle size Fe drive the highest observed ammonia production reaction rate. The Fe mass normalized rate of ammonia production increases with decreasing added mass of the Fe reactant reaching a maximum observed rate of 2.2x10<sup>-4</sup>mole of NH<sub>3</sub>h<sup>-1</sup>g<sup>-1</sup>for the reaction of 0.1 g of 1-3 µm Fe in 200°C 8 molal Na<sub>0.5</sub>K<sub>0.5</sub>OH at 15 atm. Under these conditions 5.1 wt% of the iron reacts to form NH<sub>3</sub>via the reaction N<sub>2</sub>+ 2Fe + 3H<sub>2</sub>O ®2NH<sub>3</sub>+ Fe<sub>2</sub>O<sub>3</sub>.

Lithium-ion Battery Degradation Mechanisms and Failure Analysis Methodology

2012 ◽  
Author(s):  
Bhanu Sood ◽  
Lucas Severn ◽  
Michael Osterman ◽  
Michael Pecht ◽  
Anton Bougaev ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Lithium Ion Batteries ◽  
Elevated Temperatures ◽  
Failure Process ◽  
Lithium Ion ◽  
Degradation Mechanisms ◽  
Analysis Methodology ◽  
Depth Of Discharge ◽  
Battery Degradation ◽  
Non Destructive

Abstract A review of the prevalent degradation mechanisms in Lithium ion batteries is presented. Degradation and eventual failure in lithium-ion batteries can occur for a variety of dfferent reasons. Degradation in storage occurs primarily due to the self-discharge mechanisms, and is accelerated during storage at elevated temperatures. The degradation and failure during use conditions is generally accelerated due to the transient power requirements, the high frequency of charge/discharge cycles and differences between the state-of-charge and the depth of discharge influence the degradation and failure process. A step-by-step methodology for conducting a failure analysis of Lithion batteries is presented. The failure analysis methodology is illustrated using a decision-tree approach, which enables the user to evaluate and select the most appropriate techniques based on the observed battery characteristics. The techniques start with non-destructive and non-intrusive steps and shift to those that are more destructive and analytical in nature as information about the battery state is gained through a set of measurements and experimental techniques.

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