Positive electrode for use in lithium cell and lithium cell using the same

Abstract

A positive electrode for use in a lithium battery using water as a dispersion medium, not causing a problem of deteriorating the battery performance due to corrosion of a collector or the like and not forming unevenness on the coating surface, as well as a lithium battery using the positive electrode, the positive electrode used being formed from a positive electrode paste containing a positive electrode active material represented by the following formula (I), a binder ingredient comprising a water dispersible elastomer and a water soluble polymer as a viscosity improver, water as a dispersion medium and a dispersing agent: Li x MPO 4   (I) (in the general formula (I) above, M represents a metal atom containing at least one of metal atoms selected from the group consisting of Mn, Fe, Co, Ni, Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, Al, Si, B and Mo, and 0<x<2).

1 . A positive electrode formed from a positive electrode paste comprising a positive electrode active material represented by the following general formula (I), a binder ingredient comprising a water dispersible elastomer and a water soluble polymer as a viscosity improver, water as a dispersion medium and a dispersing agent:  
         Li x MPO 4    (I)  
       (in the general formula (I) above, M represents a metal atom containing at least one of metal atoms selected from the group consisting of Mn, Fe, Co, Ni, Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, Al, Si, B and Mo, and 0<x<2).  
     
     
         2 . A positive electrode according to  claim 1 , wherein the positive electrode active material is LiFePO 4 .  
     
     
         3 . A positive electrode according to  claim 1  or  2 , wherein the dispersing agent is one or more of materials selected from the group consisting of nonionic sufactants, polycarboxylic acid compounds, compounds having a sulfonic group, and compounds having a vinyl pyrrolidone structure.  
     
     
         4 . A lithium secondary battery having a positive electrode according to  claim 1  or  2 , a negative electrode using an active material capable of intercalating/deintercalating metallic lithium or lithium ion, and an electrolyte layer.