Lithium-based solid state cells

Harwell UK are developing a solid state cell based on four very thin layers (50-60 pm each) comprising a lithium foil-polymer electrolyte-composite cathode-nickel foil current collector (lOym). 

Some successful development of rechargeable solid state systems was achieved by using lithium intercalation cathodes, such as TiS2, which operate in exactly the same manner as in the lithium-organic cells described in Chapter 7. One example of this type of cell is provided by the battery system developed in the 1970s by P. R. Mallory and Co. (now Duracell) based on the following scheme ... 

A solid-state solar cell was assembled with an ionic liquid—l-ethyl-3-methylimidazolium bis(trifluoromethanesulfone)amide (EMITFSA) containing 0.2 M lithium bis(trifluoromethanesulfone)amide and 0.2 M 4-tert-butylpyridine—as the electrolyte and Au or Pt sputtered film as the cathode.51,52 The in situ PEP of polypyrrole and PEDOT allows efficient hole transport between the ruthenium dye and the hole conducting polymer, which was facilitated by the improved electronic interaction of the HOMO of the ruthenium dye and the conduction band of the hole transport material. The best photovoltaic result ( 7p=0.62 %, 7SC=104 pA/cm2, FOC=0.716 V, and FF=0.78) was obtained from the ruthenium dye 5 with polypyrrole as the hole transport layer and the carbon-based counterelectrode under 10 mW/cm2 illumination. The use of carbon-based materials has improved the electric connectivity between the hole transport layer and the electrode.51... 

Yang, J., SnSbj.-based composite electrodes for lithium ion cells. Solid State Ionics, 135,175, 2000. 

Macklin, W. J., and Neat, R. J. (1992). Performance of titanium dioxide-based cathodes in a lithium polymer electrolyte cell. Solid State Ionics, 53, pp. 694-700. 

The first lithium/iodine cardiac pacemaker battery was implanted in 1972. This type of battery proved to be very successful in this field and for other applications, too. The special features of this solid state battery are explained with its technique, which is limited with its extremely high energy density and reliability, especially for low rate applications. This technique is based firstly on the electrode couple of lithium and iodine with its high energy content - the OCV of the lithium/iodine cell is 2.80 V -and secondly on the favorable fact that the product of the cell reaction, the lithium iodide (LiJ), forms very tight and continuous layers between the active material of the electrodes, which are acceptable ionic conductors with negligible electronic... 

---