Synthesis and Electrochemical Study of CoNi 2 S 4 as a Novel Cathode Material in a Primary Li Thermal Battery

Abstract

© The Author(s) 2017. In this work CoNi2S4was investigated as a candidate cathode material for Li thermal batteries. The CoNi2S4was synthesized by a solid state reaction at 550°C in a sealed quartz tube. Neutron powder diffraction was utilized to confirm normal spinel structure up to 200°C, however, there was cation disorder above this temperature. The electrochemical properties of the batteries were investigated at 500°C by galvanostatic discharge to elucidate the mechanism and the products NiS, Co3S4and Co9S8of the discharge mechanism were confirmed using powder X-ray diffraction. CoNi2S4exhibits two voltage plateaus vs Li13Si4at 500°C, one at 1.75 V and the second at 1.50 V. CoNi2S4has an overall capacity of 318 mA h g-1from OCV 2.58 V to 1.25 V vs Li13Si4which is comparable to that of the well-known metal disulfides.