Batteries Solid State

Van Gool, W. (ed.) (1973) Fast Ion Transport in Solids Solid-State Batteries and Devices (North-Holland, Amsterdam). 

M.Z.A. Munshi, Handbook of Solid State Batteries and Capacitors, World Scientific, Singapore, 1995. 

In solid-state batteries, it is extremely favorable to use the solid electrolyte for mechanical support. Despite the larger thickness, which lowers the relative amount for active material in the battery, the advantages are the absence of pinholes of the solid electrolyte, high electronic resistance, and simple multistack fabrication, since the individual cells may be contacted by their electronically conducting current collectors. 

Cul) is not due to point defects but to partial occupation of crystallographic sites. The defective structure is sometimes called structural disorder to distinguish it from point defects. There are a large number of vacant sites for the cations to move into. Thus, ionic conductivity is enabled without use of aliovalent dopants. A common feature of both compounds is that they are composed of extremely polarizable ions. This means that the electron cloud surrounding the ions is easily distorted. This makes the passage of a cation past an anion easier. Due to their high ionic conductivity, silver and copper ion conductors can be used as solid electrolytes in solid-state batteries. 

The perovskite structure, ABO3 (where A represents a large cation and B a medium-size cation) is adopted by many solids and solid solutions between them can readily be prepared. Vacancy-containing systems with the perovskite structure are of interest as electrolytes in solid-state batteries and fuel cells. Typical representatives of this type of material can be made by introducing a higher valence cation into the A sites or a lower valance cation into the B sites. 

Souquet, J. L. and Kone, A. (1986) in Materials for Solid State Batteries, Eds. B. V. R. Chowdari and S. Radhakrishna, World Scientific Publ. Co., Singapore. 

More recently, solid state batteries with lithium conducting polymer electrolytes have been extensively studied. The development has focused on secondary batteries for an electric vehicle, because lithium polymer batteries have a theoretical energy density that approaches 800 W h kg ... 

These studies were extended and the results used in the development of primary solid-state batteries, for operation at ambient temperatures, based on cells such as Li/LiI-CaI/AgI(C) (99a), and with Ag2Cr0tf, AgaPOt and the superlattices formed with Agl (99b). 

Layered structures are also found for many oxides and sulfides of transition metals. They can be intercalated with alkali metals (Li, Na, K) to give superconducting solids and conducting solids that are useful for solid state battery materials. 

Much of the recent research in solid state chemistry is related to the ionic conductivity properties of solids, and new electrochemical cells and devices are being developed that contain solid, instead of liquid, electrolytes. Solid-state batteries are potentially useful because they can perform over a wide temperature range, they have a long shelf life, it is possible to make them very small, and they are spill-proof We use batteries all the time—to start cars, in toys, watches, cardiac pacemakers, and so on. Increasingly we need lightweight, small but powerful batteries for a variety of uses such as computer memory chips, laptop computers, and mobile phones. Once a primary battery has discharged, the reaction cannot be reversed and it has to be thrown away, so there is also interest in solid electrolytes in the production of secondary or storage batteries, which are reversible because once the chemical reaction has taken place the reactant concentrations can be... 

The reason that solid state batteries are potentially useful is that they can perform over a wide temperature range, they have a long shelf life, and it is possible to manufacture them so that they are extremely small. Lightweight rechargeable batteries can be now be made to give sufficient power to maintain mobile phones for several days and laptop computers for several hours. They are used for backup power supplies and may eventually become useful as alternative fuel sources to power cars. 

Chapter 3 discusses solids that are not perfect. The types of defect that occnr and the way they are organized in solids forms the main subject matter. Defects lead to interesting and exploitable properties and several examples of this appear in this chapter, including photography and solid state batteries. 

Polyacetylene (n-and p-type doping) Solid state batteries ... 

Hitherto we have dealt with model FICs that are mostly useful as solid electrolytes. The other class of compounds of importance as electrode materials in solid state batteries is mixed electronic-ionic conductors (with high ionic conductivity). The conduction arises from reversible electrochemical insertion of the conducting species. In order for such a material to be useful in high-energy batteries, the extent of insertion must be large and the material must sustain repeated insertion-extraction cycles. A number of transition-metal oxide and sulphide systems have been investigated as solid electrodes (Murphy Christian, 1979). 

PEO and Related Systems. High ionic conductivities have been characteristically associated with polymer-alkali metal complexes, which are receiving great deal of research attention as electrolytes for solid state batteries. LiC104 dispersed homogeneously in cross-linked (P-cyanoethyl methylsiloxane) polyO-cyano-ethyl methylsiloxane-co-dimethylsiloxane) shows a network film conducting in the order of 10 s ohm-1 cm-1 at room temperature [106]. 

The only commercial ambient solid state batteries so far produced have been based on either silver or lithium anodes and these will now be described. 

The first commercial solid state battery was manufactured at the end of the 1960s in the USA by Gould Ionics. This was a silver-iodine battery using RbAg4I5 as electrolyte. An essential constraint on any cell system is that the active components must not react with the electrolyte either directly or by electrolytic action. Free elemental iodine reacts with RbAg4Is, degrading it to poorly conducting phases by the process... 

The high reliability and the complete absence of faults such as electrolyte leakage or gas generation make the lithium-iodine solid state battery a particularly suitable device for powering implanted electronic devices, and it is now widely used in the cardiac pacemaker industry. The design and construction of Medtronic Inc, pacemaker batteries are shown in Fig. 9.12. A typical unit, such as the Enertec Alpha 33 , has dimensions of 33.4 mm X 27.4 mm X 7.9 mm, giving a total volume of 6.0 cm3 and a mass of 22 g. The cell has a completely welded construction and uses a specialized... 

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