Materials design and optimization for thin-film microbatteries

Considerable effort has been invested in developing thin-film solid microbatteries as possible integrated components in microelectronics. Advances have been made particularly in the engineering of lithium/amorphous inorganic electrolyte/layered compound cells fabricated using various evaporation techniques. The main features of these cells are influenced by the characteristics of the fast ionic conductor and the insertion compound layers which are discussed in detail in this work. Design and optimization of lithium-microbattery components are discussed. Different electrochemical systems using lithium borate-glass films as solid electrolytes have been fabricated and characterized. Thin-film active cathodic materials include transition-metal dichalcogenides such as TiS₂, MoS₂, non-transition-metal chalcogenides such as InSe and transition-metal oxides such as MoO₃, V₂O₅, V₆O₁₃ films. Particular attention is paid to the structural and transport properties of these materials and their behaviour in electrochemical lithium cells are presented. Thermodynamics and kinetics are studied as functions of the growth conditions of thin-film components. The physical properties are discussed in relation to the electrochemical cell behavior and battery performance. Paper presented at the 1st Euroconference on Solid State Ionics, Zakynthos, Greece, 11–18 Sept. 1994.