The lithium/thionyl chloride (Li/SOCl 2 ) cell has one of the highest specific energies of any developed primary (non-rechargeable) battery. Large capacity, low rate (low power) cells have been built that can deliver a practical specific energy of 500 Wh/kg. The system has an open circuit voltage of 3.66 V and typically operates in the 3.3 to 3.5 V range. Li/SOCl 2 batteries perform well over a wide temperature range (-40 to 80°C) and are still functional at temperatures as high as 145°C. The lithium/thionyl chloride cell consists of a lithium anode, an inert carbon cathode and a non-aqueous electrolyte. SOCl 2 is both the liquid electrolyte and the active cathode material - the material that undergoes reduction upon the discharge of the battery. The electrolyte is composed of thionyl chloride, (SOCl 2 ), lithium chloride, (LiCl), and aluminum trichloride, (AlCl 3 ). As SOCl 2 has a very low conductivity, it is necessary to add conductive salts to facilitate Li + ion traort. Typically LiAlCl 4 (LiCl and AlCl 3 ) is used, both because it is readily soluble in SOCl 2 , and because it is relatively inexpensive. Commercial cells also include proprietary additives to improve cell performance. Additives such as polyvinyl chloride for control of voltage delay. In this thesis, the effect of adding graphene-based cobalt nanoparticles to the cathode support on electrochemical reduction of thionyl chloride in lithium thionyl chloride battery has been investigated. Acetylene black (100% compressed) and PTFE dispersion (60 wt%) were applied for preparation of cathode support composite material. For the preparation of the cathode substrate, Co/rGO nanocatalyst was applied in two procedures: a) Mechanical mixing and subsequently evaluating the electrochemical performance of the battery and b) preparation of composite and then performing the electrochemical measurements. Obtained results showed that adding Co/rGO nanocatalyst in both procedures significantly enhances the battery electrochemical performance. This effect remarkably can be observed in second procedure due to synergism effect of both enhancing the charge transfer process and surface area increasement. This catalytic activity of cobalt atoms can be related to the electronic configuration of d orbitals.
