(US5705534-A)      Prepn. of a modified cation exchange membrane in which a sulphide of Ag, W, Mo or a mixt. of these is deposited within the polymer matrix comprises: (a) forming within the polymer matrix of the membrane a complex of Ag, W, Mo or a mixt. of these with a water soluble cpd. contg. an -SH gp.; and (b) converting the complex into the insoluble sulphide of Ag, W, Mo or mixt. of these.    USE -   The modified cation exchange membrane is useful in various electrochemical applications, pref. in appts. for energy storage and/or power delivery.    ADVANTAGE -   The method overcomes the disadvantages of the method disclosed in PCT/GB95/00668 in which the metal sulphide is pptd. either at the membrane surface or in the region of the polymer matrix adjacent to the membrane surface, and a deficient band is left in the centre of the membrane.    (ZA9607996-A)      Prepn. of a modified cation exchange membrane in which a sulphide of Ag, W, Mo or a mixt. of these is deposited within the polymer matrix comprises: (a) forming within the polymer matrix of the membrane a complex of Ag, W, Mo or a mixt. of these with a water soluble cpd. contg. an -SH gp.; and (b) converting the complex into the insoluble sulphide of Ag, W, Mo or mixt. of these.    USE -   The modified cation exchange membrane is useful in various electrochemical applications, pref. in appts. for energy storage and/or power delivery.    ADVANTAGE -   The method overcomes the disadvantages of the method disclosed in PCT/GB95/00668 in which the metal sulphide is pptd. either at the membrane surface or in the region of the polymer matrix adjacent to the membrane surface, and a deficient band is left in the centre of the membrane.    (EP873372-A1)      Prepn. of a modified cation exchange membrane in which a sulphide of Ag, W, Mo or a mixt. of these is deposited within the polymer matrix comprises: (a) forming within the polymer matrix of the membrane a complex of Ag, W, Mo or a mixt. of these with a water soluble cpd. contg. an -SH gp.; and (b) converting the complex into the insoluble sulphide of Ag, W, Mo or mixt. of these.    USE -   The modified cation exchange membrane is useful in various electrochemical applications, pref. in appts. for energy storage and/or power delivery.    ADVANTAGE -   The method overcomes the disadvantages of the method disclosed in PCT/GB95/00668 in which the metal sulphide is pptd. either at the membrane surface or in the region of the polymer matrix adjacent to the membrane surface, and a deficient band is left in the centre of the membrane.    (JP11511502-W)      Prepn. of a modified cation exchange membrane in which a sulphide of Ag, W, Mo or a mixt. of these is deposited within the polymer matrix comprises: (a) forming within the polymer matrix of the membrane a complex of Ag, W, Mo or a mixt. of these with a water soluble cpd. contg. an -SH gp.; and (b) converting the complex into the insoluble sulphide of Ag, W, Mo or mixt. of these.    USE -   The modified cation exchange membrane is useful in various electrochemical applications, pref. in appts. for energy storage and/or power delivery.    ADVANTAGE -   The method overcomes the disadvantages of the method disclosed in PCT/GB95/00668 in which the metal sulphide is pptd. either at the membrane surface or in the region of the polymer matrix adjacent to the membrane surface, and a deficient band is left in the centre of the membrane.    (EP873372-B1)      Prepn. of a modified cation exchange membrane in which a sulphide of Ag, W, Mo or a mixt. of these is deposited within the polymer matrix comprises: (a) forming within the polymer matrix of the membrane a complex of Ag, W, Mo or a mixt. of these with a water soluble cpd. contg. an -SH gp.; and (b) converting the complex into the insoluble sulphide of Ag, W, Mo or mixt. of these.    USE -   The modified cation exchange membrane is useful in various electrochemical applications, pref. in appts. for energy storage and/or power delivery.    ADVANTAGE -   The method overcomes the disadvantages of the method disclosed in PCT/GB95/00668 in which the metal sulphide is pptd. either at the membrane surface or in the region of the polymer matrix adjacent to the membrane surface, and a deficient band is left in the centre of the membrane.