Inorganic polymer electrolytes

A. Banerjee, M. K. Ravikumar, A. Jalajakshi, S. A. Gaffoor and A. K. Shukla, A 12 V substrate-integrated Pb02-activated carbon asymmetric hybrid ultracapacitor with silica-gel based inorganic-polymer electrolyte, ECS Trans. 41, 2012... 

The successfiil synthesis of a transparent soHd polymer electrolyte (SPE) based on PEO and alkoxysilanes has been reported (41). The material possessed good mechanical properties and high electrical conductivity (around 1.8 x 10 S/cm at 25°C) dependent on the organic—inorganic ratio and PEO chain length. 

The desire to realise technological goals has spurred the discovery of many new solid electrolytes and intercalation compounds based on crystalline and amorphous inorganic solids. In addition an entirely new class of ionic conductors has been discovered by P. V. Wright (1973) and M. B. Armand, J. M. Chabagno and M. Duclot (1978). These polymer electrolytes can be fabricated as soft films of only a few microns, and their flexibility permits interfaces with solid electrodes to be formed which remain intact when the cells are charged and discharged. This makes possible the development of all-solid-state electrochemical devices. 

The structures and charge transport mechanisms for polymer electrolytes differ greatly from those of inorganic solid electrolytes, therefore the purpose of this chapter is to describe the general nature of polymer electrolytes. We shall see that most of the research on new polymer electrolytes has been guided by the principle that ion transport is strongly dependent on local motion of the polymer (segmental motion) in the vicinity of the ion. 

At this time the only commercially available all-solid-state cell is the lithium battery containing Lil as the electrolyte. Many types of solid lithium ion conductors including inorganic crystalline and glassy materials as well as polymer electrolytes have been proposed as separators in lithium batteries. These are described in the previous chapters. A suitable solid electrolyte for lithium batteries should have the properties... 

These examples and the general subjects mentioned above illustrate that ion conduction and the electrochemical properties of solids are particularly relevant in solid state ionics. Hence, the scope of this area considerably overlaps with the field of solid state electrochemistry, and the themes treated, for example, in textbooks on solid state electrochemistry [27-31] and books or journals on solid state ionics [1, 32] are very similar indeed. Regrettably, for many years solid state electrochemistry/solid state ionics on the one hand, and liquid electrochemistry on the other, developed separately. Although developments in the area of polymer electrolytes or the use of experimental techniques such as impedance spectroscopy have provided links between the two fields, researchers in both solid and liquid electrochemistry are frequently not acquainted with the research activities of the sister discipline. Similarities and differences between (inorganic) solid state electrochemistry and liquid electrochemistry are therefore emphasized in this review. In Sec. 2, for example, several aspects (non-stoichiometry, mixed ionic and electronic conduction, internal interfaces) are discussed that lead to an extraordinary complexity of electrolytes in solid state electrochemistry. 

Unlike hard inorganic electrolytes, polymer electrolytes can deform under stress. This makes them extremely promising... 

Baradie, B., Dodelet, J.R, and Guay, D., Hybrid Nafion -inorganic membrane with potential applications for polymer electrolyte fuel cells, J. Electroanal. Chem., 489, 101, 2000. 

PM Hybrid Inorganic-Organic Polymer Composites for Polymer-Electrolyte Fuel Cells ... 

In devices, diverse types of electrolytes have been used, such as liquid, solid inorganic bulk type, or thin film and solid organic polymer electrolytes. 

This review deals with several types of polymer hosts that have been investigated. These include polyethylene oxide and its several modified forms, comb like polymers such as polyacrylates and inorganic polymers such as polyphosphazenes and polysiloxanes. Various instrumental techniques have been employed in the structural characterization of polymer electrolytes. The structural information obtained from methods such as Extended X-ray Absorption Fine Structure (EXAFS), X-ray diffraction methods, vibrational spectroscopy and nuclear magnetic resonance (NMR) have also been discussed. 

Polymers that function as solid electrolytes are a subclass by themselves and are known as polymer electrolytes [27,29]. Besides the advantage of flexibility, polymers can also be cast into thin films and since thin films while minimizing the resistance of the electrolyte also reduces the volume and the weight, use of polymer electrolytes can increase the energy stored per unit weight and volume. In view of these attractive features, there has been considerable focus in recent years on the development of both inorganic and organic polymers as electrolytes for ion transport. This article deals with the recent developments in this area with emphasis on the new types of polymeric systems that have been used as polymer electrolytes. 

Another kind of modification of PEO involves the concept of composite polymer electrolytes [33, 37-38, 138-144]. These include the use of inorganic fillers such asNASICON [138],/1-alumina [139], glassy fillers [139] y-LiA 02 [140-143]... 

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