Organic Liquid Electrolytes

Ue M, Ida K, Mori S. Electrochemical properties of organic liquid electrolytes based on quaternary onium salts for electrical double-layer capacitors. Journal of the Electrochemical Society 1994 141(ll) 2989-2995. 

Maeshima, H., H. Moriwake, A. Kuwabara, C. A. J. Fisher, and I. Tanaka. 2014. An improved method for quantitatively predicting the electrochemical stabilities of organic liquid electrolytes using ab initio calculations. Journal of the Electrochemical Society 161 G7-G14. 

The similarity in the ionic transport mechanism in organic liquid electrolytes and solid polymer electrolytes is reflected in the ionic transport numbers measured in the two media. Table 3.5 lists the transport numbers for Li in LiC104 solutions in propylene carbonate (PC) and propylene carbonate/dimethoxy ethane (PC/DME) mixtures [26]. The t+ in PC/LiC104 is 0.28 which increases to between 0.40 and 0.50 with the addition of DME. This increase in t+ in PC/DME mixtures may reflect a change in the solvation characteristics of Li, and/or ionic species present, with the addition of DME. It is then possible that a range of cation transference numbers between 0.2 and 0.6 measured in polymer electrolytes is a reflection of the coordination properties of the particular polymer host with Li" and the nature of the ionic species present. 

Because of the similarity in the conductivity mechanism of polymer electrolytes and organic liquid electrolytes, the significance of the relationships in equations [3.6] and [3.7] can be understood qualitatively from an examination of the conductivities of some liquid electrolytes. Table 3.6 lists the conductivities of LiAsFg (1 molar) in four different solvents. LiAsFs is a... 

An atomistic simulation MD simulation of a common carbonate-based organic electrolyte, ethylene carbonate dimethyl carbonate (EC DMC = 3 7) with approximately 1 mol/kg LiPFs, referred to as the organic liquid electrolyte or OLE, and an ionic liquid-based electrolyte (ILE), 1-ethyl 3-methyl-imidazolium bis (fluorosulfonyl)imide (EMIM iFSE) with 1 mol/kg LiFSI, in contact with LiFeP04 has been carried out [107]. Simulations were carried out using quantum chemistry-based polarizable force at 363 K on a 3-D periodic orthorhombic... 

Fig. 7.28 Poisson potential and Li free energy as a fimction of position with respect to the interface with LiFeP04 in an organic liquid electrolyte...

As described above, a lithium-ion conducting solid electrolyte is a key material necessary to establish all-solid-state lithium-ion batteries. To date, much effort has been devoted to creating superior lithium-ion conductors comparable to organic liquid electrolytes. 

Much attention has been paid to a variety of inorganic solid electrolytes (Li7P3Sn [18] etc.) and its application to all-solid-state lithium-ion batteries. Since the transference number of the inorganic solid electrolyte is almost unity, the lithium-ion conductivity of the solid electrolyte is almost comparable to that of organic liquid electrolyte. However, in spite of the presence of highly lithium-ion conductive solid electrolytes, the all-solid-state batteries had not provided sufficient power densities until recendy. One of the critical reasons for the limited power density was due to the large lithium-ion transfer resistance at the interface between cathode and solid electrolyte. 

A Li-S battery comprises a positive electrode of elementary sulfur (Sg), an organic liquid electrolyte and a negative electrode of metal lithiiun. More specifically, the positive electrode is usually composite, i.e. prepared using elementary sulfur and non-electroactive adjuvants. A finely powdered electronic conductor (carbon black or acetylene black) is used to improve the... 

Aprotic Organic Electrolytes. Aprotic liquid organic electrolyte solvents, such as dioxo-lane, propylene carbonate, ethylene carbonate, diethyl carbonate and ethylmethyl carbonate are the most common electrolyte solvents because of their low reactivity with lithium. A list of the electrolyte solvents used in rechargeable lithium batteries with their major characteristics is given in Table 34.8. Choices for the electrolyte solute and their ionic conductivities in various solvents at different temperatures are listed in Table 34.9. These organic liquid electrolytes generally have conductivities that are about two orders of magnitude lower than aqueous electrolytes. 

TABLE 34.9 Ionic Conductivity of Some 1 Molar Organic Liquid Electrolytes Used in Secondary Lithium Battery Systems... 

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