Nonaqueous secondary battery and separator

Abstract

A secondary battery in which convection in an electrolyte solution occurs easily is provided. A secondary battery whose electrolyte solution can be replaced is provided. A nonaqueous secondary battery includes a positive electrode, a negative electrode, a separator, and an electrolyte solution, and the separator includes grooves capable of making convection in the electrolyte solution occur easily. The nonaqueous secondary battery has at least one expected installation direction, and the grooves in the separator are preferably formed so as to be perpendicular to an expected installation surface. The exterior body includes a first opening for injection of an inert gas into the exterior body and a second opening for expelling or injection of an electrolyte solution from or into the exterior body. An electrolyte solution replacement apparatus has a function of injecting the inert gas through the first opening and expelling or injecting the electrolyte solution through the second opening.

What is claimed is: 
     
         1 . A secondary battery comprising a positive electrode, a negative electrode, an electrolyte solution, and a separator,
 wherein the separator at least partly includes a groove parallel to the positive electrode and the negative electrode.   
     
     
         2 . A secondary battery comprising:
 a positive electrode;   a negative electrode; and   a separator between the positive electrode and the negative electrode,   wherein the separator includes a plurality of grooves in a direction perpendicular to an installation surface for the secondary battery.   
     
     
         3 . The secondary battery according to  claim 2 , wherein a cross-section of the plurality of grooves has a curved shape. 
     
     
         4 . The secondary battery according to  claim 2 , wherein a cross-section of the plurality of grooves has a trapezoidal shape. 
     
     
         5 . The secondary battery according to  claim 2 , wherein the plurality of grooves are provided in a disconnected manner. 
     
     
         6 . A secondary battery comprising:
 a positive electrode;   a negative electrode;   a separator between the positive electrode and the negative electrode;   an electrolyte solution; and   an exterior body covering the positive electrode, the negative electrode, the separator, and the electrolyte solution,   wherein the exterior body comprises a first opening for injection of an inert gas into the exterior body and a second opening for expelling or injection of the electrolyte solution from or into the exterior body, and   wherein the separator includes a plurality of grooves in a direction perpendicular to an installation surface for the secondary battery.   
     
     
         7 . The secondary battery according to  claim 6 , wherein a cross-section of the plurality of grooves has a curved shape. 
     
     
         8 . The secondary battery according to  claim 6 , wherein a cross-section of the plurality of grooves has a trapezoidal shape. 
     
     
         9 . The secondary battery according to  claim 6 , wherein the plurality of grooves are provided in a disconnected manner. 
     
     
         10 . The secondary battery according to  claim 6 , wherein the inert gas is a nitrogen gas. 
     
     
         11 . The secondary battery according to  claim 6 , wherein the first opening is provided on an upper surface of the exterior body. 
     
     
         12 . The secondary battery according to  claim 6 , wherein the second opening is provided on a side surface of the exterior body. 
     
     
         13 . A secondary battery comprising:
 a positive electrode;   a negative electrode;   a separator between the positive electrode and the negative electrode;   an electrolyte solution; and   an exterior body covering the positive electrode, the negative electrode, the separator, and the electrolyte solution,   wherein the exterior body comprises a first opening for injection of an inert gas into the exterior body and a second opening for expelling or injection of the electrolyte solution from or into the exterior body,   wherein the separator comprises a first region and a second region, and   wherein a thickness of the first region is less than or equal to 80% of a thickness of the second region.   
     
     
         14 . The secondary battery according to  claim 13 , wherein the inert gas is a nitrogen gas. 
     
     
         15 . The secondary battery according to  claim 13 , wherein the first opening is provided on an upper surface of the exterior body. 
     
     
         16 . The secondary battery according to  claim 13 , wherein the second opening is provided on a side surface of the exterior body. 
     
     
         17 . The secondary battery according to  claim 13 , wherein the first region has an uneven surface.