FeS2 has been widely used for cathode materials in thermal battery because of its high stability and currentcapability at high operation temperature. Salts such as a LiCl-KCl were added as a binder for improving electrical per-formance and formability of FeS2 cathode powder. In this study, the effects of the addition of Li2O in LiCl-KCl binderon the formability of FeS2 powder compact were investigated. With the increasing amount of Li2O addition to LiCl-KClbinder salts, the strength of the pressed compacts increased considerably when the powder mixture were pre-heat-treatedabove 350oC. The heat-treatment resulted in promoting the coating coverage of FeS2 particles by the salts as Li2O wasadded. The observed coating as Li2O addition might be attributed to the enhanced wettability of the salt rather than itsreduced melting temperature. The high strength of compacts by the Li2O addition and pre-heat-treatment could improvethe formability of FeS2 raw materials.