Bipolar battery current collector and bipolar battery

Abstract

Provided is a bipolar battery current collector that includes a conductive resin layer formed in such a manner as to, when at least part of the conductive resin layer reaches a predetermined temperature, interrupts a flow of electric current through the at least part of the conductive resin layer in a vertical direction thereof. Also provided is a bipolar battery using the current collector. It is possible by the use of the current collector to suppress local heat generation in the bipolar battery and improve the durability of the bipolar battery.

1 . A bipolar battery current collector, comprising:
 a conductive resin layer containing a thermoplastic resin and formed in such a manner as to, when at least part of the conductive resin layer reaches a predetermined temperature, interrupts a flow of electric current through the at least part of the conductive resin layer in a vertical direction thereof.   
     
     
         2 . The bipolar battery current collector according to  claim 1 , wherein the at least part of the conductive resin layer contracts when reaching the predetermined temperature. 
     
     
         3 . The bipolar battery current collector according to  claim 1 , wherein the conductive resin layer has a plurality of pores formed therein. 
     
     
         4 . The bipolar battery current collector according to  claim 3 , wherein the porosity of at least one of positive- and negative-electrode-side surfaces of the conductive resin layer is higher than the porosity of a center portion of the conductive resin layer. 
     
     
         5 . The bipolar battery current collector according to  claim 3 , wherein the size of the pores present in at least one of positive- and negative-electrode-side surfaces of the conductive resin layer is larger than the size of the pores present in a center portion of the conductive resin layer. 
     
     
         6 . The bipolar battery current collector according to  claim 1 , wherein the conductive resin layer contains a first polymer and a second polymer; and wherein the first polymer has a melting point lower than a melting point of the second polymer so that at least part of the first polymer melts when the at least part of the conductive resin layer reaches the predetermined temperature. 
     
     
         7 . The bipolar battery current collector according to  claim 6 , wherein the conductive resin layer comprises a low melting layer containing the first polymer and a high melting layer containing the second polymer. 
     
     
         8 . The bipolar battery current collector according to  claim 7 , wherein the low melting layer containing the first polymer is located on at least one surface of the high melting layer containing the second polymer. 
     
     
         9 . The bipolar battery current collector according to  claim 6 , wherein the conductive resin layer comprises a high melting layer containing the second polymer and low melting particles containing the first polymer and located in the high melting layer. 
     
     
         10 . The bipolar battery current collector according to  claim 9 , wherein the low melting particles containing the first polymer are located in a surface of the high melting layer containing the second polymer. 
     
     
         11 . The bipolar battery current collector according to  claim 10 , wherein the high melting layer containing the second polymer has a plurality of pores formed therein. 
     
     
         12 . A bipolar battery comprising: the bipolar battery current corrector according to  claim 1 . 
     
     
         13 . The bipolar battery current collector according to  claim 2 , wherein the conductive resin layer has a plurality of pores formed therein. 
     
     
         14 . The bipolar battery current collector according to  claim 4 , wherein the size of the pores present in at least one of positive- and negative-electrode-side surfaces of the conductive resin layer is larger than the size of the pores present in a center portion of the conductive resin layer.