(US5882812-A)      A rechargeable electrochemical energy conversion device (I) resisting damage from overcharge comprises: (a) a positive electrode other than a sulphur electrode; (b) a negative electrode; (c) a sulphur-based additive including at least of one elemental sulphur, sulphide species and a polysulphide species; and (d) an electrolyte in which the polysulphide species are substantially soluble and the sulphide species are substantially insoluble.    During overcharge, a polysulphide species is oxidised which is subsequently reduced by a reaction with the substantially insoluble sulphide species.    Also claimed are: (1) a method of providing protection against overcharge damage comprising providing the above device (I) and overcharging such that the above overcharge reaction occurs; (2) another rechargeable electrochemical energy conversion device (II) resisting damage from overcharge comprising: (i) a negative electrode; (ii) a positive electrode containing one or more intermediate species which are oxidised to one or more oxidised species during overcharge, which can move to the negative electrode where they are reduced back to the intermediate species, the oxidised species reacting more rapidly than the intermediate species at the negative electrode; and (iii) a tuning species which adjusts the rate at which the oxidised species are reduced and thereby adjusts the voltage at which overcharge protection is provided; and (3) a method of providing protection against overcharge damage comprising providing the above device (II) and overcharging such that the above overcharge reaction occurs.    USE -   The device is sued to protect the mechanism from overcharging.    ADVANTAGE -   The employed protective species resist attack by lithium, are stable in reduced and oxidised states and do not impede the cell's normal charge and discharge functioning.    (US6248481-B1)      A rechargeable electrochemical energy conversion device (I) resisting damage from overcharge comprises: (a) a positive electrode other than a sulphur electrode; (b) a negative electrode; (c) a sulphur-based additive including at least of one elemental sulphur, sulphide species and a polysulphide species; and (d) an electrolyte in which the polysulphide species are substantially soluble and the sulphide species are substantially insoluble.    During overcharge, a polysulphide species is oxidised which is subsequently reduced by a reaction with the substantially insoluble sulphide species.    Also claimed are: (1) a method of providing protection against overcharge damage comprising providing the above device (I) and overcharging such that the above overcharge reaction occurs; (2) another rechargeable electrochemical energy conversion device (II) resisting damage from overcharge comprising: (i) a negative electrode; (ii) a positive electrode containing one or more intermediate species which are oxidised to one or more oxidised species during overcharge, which can move to the negative electrode where they are reduced back to the intermediate species, the oxidised species reacting more rapidly than the intermediate species at the negative electrode; and (iii) a tuning species which adjusts the rate at which the oxidised species are reduced and thereby adjusts the voltage at which overcharge protection is provided; and (3) a method of providing protection against overcharge damage comprising providing the above device (II) and overcharging such that the above overcharge reaction occurs.    USE -   The device is sued to protect the mechanism from overcharging.    ADVANTAGE -   The employed protective species resist attack by lithium, are stable in reduced and oxidised states and do not impede the cell's normal charge and discharge functioning.