Positive active material mfr. - by reacting lithium sulphide and ferrous sulphide hot for one to three weeks

摘要

Method of mfr. of positive active material for an electrochemical generator with liq. electrolyte as described in the parent patent, is claimed, the material being of formula AxMgSz where A is an alkali metal (Li, Na or It) M is a transition metal (Fe, Cu, Pb or Ni) SuS or Se. x is 0-2, y is 1-2 and Z is 1-4. In this addn. the pref. cpds. are LixFeSz and LixFezS3+ The method comprises mixing 1 mole Li2S with 1 or 2 moles FeS, heating the mixt. in a sealed ampoule at not above 885 deg.C for 1-3 weeks to obtain the respective cpds. These cpds. have esp. interesting electrochemical properties partic. a high stable capacity even after a number of charge/discharge cycles, and a remarkable reversibility.