Solid-electrolyte batteries advantages

Solid Electrolyte Systems. Whereas there has been considerable research into the development of solid electrolyte batteries (18—21), development of practical batteries has been slow because of problems relating to the low conductivity of the solid electrolyte. The development of an all solid-state battery would offer significant advantages. Such a battery would overcome problems of electrolyte leakage, dendrite formation, and corrosion that can be encountered with liquid electrolytes. 

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. 

The ion solvating polymers have found application mainly in power sources (all-solid lithium batteries, see Fig. 2.19), where polymer electrolytes offer various advantages over liquid electrolyte solutions. 

Numerous other battery chemistries have evolved over time. The most prominent ones are assembled in Table 3.5.2. One possible categorization of battery technologies can be made according to the class of electrolyte they use. Here, we will distinguish between liquid aqueous, liquid nonaqueous, and solid electrolytes. To a certain degree, the phase state of the electrolyte determines the state of the electrodes. In general, it is advantageous to have a solid/liquid phase boundary between electrode and electrolyte because of much lower contact resistance in comparison to solid/solid contacts. Therefore, if the electrodes are solids, the electrolyte should be preferably liquid and vice versa. 

Solid electrolytes for lithium-ion batteries are expected to offer several advantages over traditional, nonaqueous liquid electrolytes. A solid electrolyte would give a longer shelf life, along with an enhancement in specific energy density. A solid electrolyte may also eliminate the need for a distinct separator material, such as the polypropylene or polyethylene microporous separators commonly used in contemporary liquid electrolyte-based batteries. Solid electrolytes are also desirable over liquid electrolytes in certain specialty applications where bulk lithium-ion batteries as weU as thin-film lithium-ion batteries are needed for primary and backup power supplies for systems, devices, and individual integrated circuit chips. 

An alternative to employing liquid electrolytes is to use a solid electrolyte to produce an all solid battery. This may have several advantages—an absence of electrolyte leakage or gassing, the likelihood of an extremely long shelf-life, and the capability of operating over a wide temperature range. 

A solid protonic electrolyte battery presents the general advantages of all solid-state systems such as absence of liquid leakage and ease of handling. It must have two electrodes to react with the protons, as in aqueous liquid electrolyte batteries. The main aim for using solid protonic conductors resides in the possibility of using similar electrodes to those in current commercial batteries. 

Another advantage is the improved safety of the battery because there is no risk of liquid electrolyte leaking and because of high thermal stability attributed to nonflammable and inorganic solid electrolytes. 

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