Shelf life lithium solid electrolyte

Lithium solid electrolyte Very long shelf life but used only for low power applications Medical electronics and implantable devices... 

Lithium/solid electrolyte Extremely long shelf life low-power battery Medical electronics, memory circuits, fusing... 

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. 

Scrosati and coworkers [165] have fabricated an all solid lithium battery by combining a PAN based polymer electrolyte (containing EC and PC) with a lithium metal anode and a poly pyrrole (pPy) film cathode. Although the Coulom-bic efficiency was found to be high, near 90%, the battery has a poor shelf life. 

Primary batteries have existed for over 100 years, but up to 1940, the zinc-carbon battery was the only one in wide use. During World War II and the postwar period, significant advances were made, not only with the zinc-carbon system, but with new and superior types of batteries. Capacity was improved from less than 50 Wh/kg with the early zinc-carbon batteries to more than 400 Wh/kg now obtained with lithium batteries. The shelf life of batteries at the time of World War n was limited to about 1 year when stored at moderate temperatures the shelf life of present-day conventional batteries is from 2 to 5 years. The shelf life of the newer lithium batteries is as high as 10 years, with a capability of storage at temperatures as high as 70°C. Low-temperature operation has been extended from 0 to -40C, and the power density has been improved manyfold. Special low-drain batteries using a solid electrolyte have shelf lives in excess of 20 years. 

A lithium ion conducting solid electrolyte such as lithium iodide or lithium iodide-f alumina (33 mol%). The lithium iodide solid electrolyte is formed as a very thin film by directly contacting lithium metal with the positive electrode material, iodine, complexed with polyvinylpyridine. Such cells are only capable of discharge at a low rate (< 100 pAcm" ), at ambient temperatures but they perform excellently when only required to provide a low power, e.g. for a heart pacemaker. The lifetime in service can be many years and the shelf-life during storage is also long. 

---