Electrode assembly and secondary battery

Abstract

The present disclosure provides an electrode assembly and a secondary battery. The electrode assembly includes a first electrode plate, a second electrode plate and a separator. The first electrode plate, the second electrode plate and the separator are wound to a flat structure, and the flat structure comprises a main region and corner regions, the corner regions are provided at two ends of the main region along a width direction of the main region. The first electrode plate and the second electrode plate each are wound to turns. A gap is provided between two adjacent turns of the first electrode plate, the gap includes a first gap and a second gap. The first gap corresponds to the corner region in position, the second gap corresponds to the main region in position, and a dimension of the first gap is larger than a dimension of the second gap.

What is claimed is: 
     
         1 . An electrode assembly, comprising:
 a first electrode plate;   a second electrode plate having an outer side and an inner side;   a first separator positioned at and adjacent to the outer side of the second electrode plate; and   a second separator disposed between the first electrode plate and the second electrode plate and adjacent to the inner side of the second electrode plate,   wherein the electrode assembly is configured in a wound structure having a plurality of turns including a first turn and a second turn, the first turn is outwardly adjacent to the second turn, and the first electrode plate of the first turn is outwardly adjacent to the first separator of the second turn,   wherein the wound structure comprises:
 a main region; and 
 a comer region positioned at an end of the main region and along a width direction of the main region, 
   wherein a first gap and a second gap are formed between the first electrode plate of the first turn and the first separator of the second turn, the first gap corresponds to the comer region in position, the second gap corresponds to the main region in position, and the first gap is larger than the second gap in dimension.   
     
     
         2 . The electrode assembly of  claim 1 , wherein a third gap and a fourth gap are formed between the second electrode plate and the first separator adjacent to the second electrode plate, the third gap corresponds to the comer region in position, the fourth gap corresponds to the main region in position, and the third gap is larger than the fourth gap in dimension. 
     
     
         3 . The electrode assembly of  claim 1 , wherein the second electrode plate comprises a plurality of first protrusions and a plurality of second protrusions, the first protrusions correspond to the comer region in position, the second protrusions correspond to the main region in position, the first protrusions and the second protrusions protrude from the outer side of the second electrode plate outwardly to the first separator adjacent to the second electrode plate. 
     
     
         4 . The electrode assembly of  claim 3 , wherein a height of the first protrusions is larger than a height of the second protrusions. 
     
     
         5 . The electrode assembly of  claim 4 , wherein the height of the first protrusions is less than 80 μm, and the height of the second protrusions is less than 20 μm. 
     
     
         6 . The electrode assembly of  claim 1 , wherein a dimension ratio of the first gap to the second gap is less than 16. 
     
     
         7 . The electrode assembly of  claim 1 , wherein the first gap has a dimension from 20 μm to 80 μm, and the second gap has a dimension from 5 μm to 20 μm. 
     
     
         8 . The electrode assembly of  claim 1 , wherein the first electrode plate is a negative electrode plate, and the second electrode plate is a positive electrode plate. 
     
     
         9 . The electrode assembly of  claim 3 , wherein a first recess is formed at an inner side of at least one of the first protrusions, and a second recess is formed at an inner side of at least one of the second protrusions. 
     
     
         10 . The electrode assembly according to  claim 1 , wherein a ratio of a width of the main region to a thickness of the main region is 5-20. 
     
     
         11 . The electrode assembly according to  claim 1 , wherein the wound structure has an even number of layers of the first electrode plate and an even number of layers of the second electrode plate in the main region. 
     
     
         12 . An electrode assembly, comprising:
 a first electrode plate;   a second electrode plate having an outer side and an inner side;   a first separator positioned at and adjacent to the outer side of the second electrode plate; and   a second separator disposed between the first electrode plate and the second electrode plate and adjacent to the inner side of the second electrode plate,   wherein the electrode assembly is configured in a wound structure having a plurality of turns including a first turn and a second turn, the first turn is outwardly adjacent to the second turn, and the first electrode plate of the first turn is outwardly adjacent to the first separator of the second turn,   wherein the wound structure comprises:
 a main region; and 
 a comer region positioned at an end of the main region and along a width direction of the main region, 
   wherein a first gap and a second gap are formed between the first electrode plate of the first turn and the first separator of the second turn, the first gap corresponds to the comer region in position, the second gap corresponds to the main region in position, and the first gap is larger than the second gap in dimension,   wherein a third gap and a fourth gap are formed between the second electrode plate and the first separator adjacent to the second electrode plate, the third gap corresponds to the comer region in position, the fourth gap corresponds to the main region in position,   wherein the second electrode plate comprises a plurality of first protrusions and a plurality of second protrusions, the first protrusions correspond to the comer region in position, the second protrusions correspond to the main region in position, the first protrusions disposed in the third gap and protrude from the outer side of the second electrode plate outwardly, and the second protrusions disposed in the fourth gap and protrude from the outer side of the second electrode plate outwardly.   
     
     
         13 . The electrode assembly of  claim 12 , wherein the third gap has a dimension equal to a height of the first protrusions, and the fourth gap has a dimension equal to a height of the second protrusions. 
     
     
         14 . The electrode assembly of  claim 13 , wherein the third gap is larger than the fourth gap in dimension. 
     
     
         15 . The electrode assembly of  claim 14 , wherein a dimension of the third gap is less than 80 μm, and a dimension of the fourth gap is less than 20 μm. 
     
     
         16 . The electrode assembly of  claim 12 , wherein the second electrode plate comprises a first region and a second region, the first region corresponds to the comer region in position, the second region extends from an end of the first region and corresponds to the main region in position, the first protrusions are within the first region, the second protrusions are within the second region, a ratio of a total area of the first protrusions to an area of the first region is from 50% to 90%, and a ratio of a total area of the second protrusions to an area of the second region is from 50% to 90%. 
     
     
         17 . A secondary battery comprising a case, a cap assembly, and an electrode assembly,
 wherein the case comprises an accommodating cavity, the electrode assembly is disposed in the accommodating cavity, and the cap assembly is connected with the case,   wherein the electrode assembly comprises:
 a first electrode plate; 
 a second electrode plate having an outer side and an inner side; 
 a first separator positioned at and adjacent to the outer side of the second electrode plate; and 
 a second separator disposed between the first electrode plate and the second electrode plate and adjacent to the inner side of the second electrode plate, 
   wherein the electrode assembly is configured in a wound structure having a plurality of turns including a first turn and a second turn, the second turn is outwardly adjacent to the first turn, and the first electrode plate of the first turn is positioned adjacent to the first separator of the second turn,   wherein the wound structure comprises:
 a main region; and 
 a comer region, the comer region positioned at an end of the main region and along a width direction of the main region, 
   wherein a first gap and a second gap are formed between the first electrode plate of the first turn and the first separator of the second turn, the first gap corresponds to the comer region in position, the second gap corresponds to the main region in position, and the first gap is larger than the second gap in dimension.   
     
     
         18 . The secondary battery of  claim 17 , wherein a third gap and a fourth gap are formed between the second electrode plate and the first separator adjacent to the second electrode plate, the third gap corresponds to the comer region in position, the fourth gap corresponds to the main region in position, and the third gap is larger than the fourth gap in dimension. 
     
     
         19 . The secondary battery of  claim 17 , wherein the second electrode plate comprises a plurality of first protrusions and a plurality of second protrusions, the first protrusions correspond to the comer region in position, the second protrusions correspond to the main region in position, the first protrusions and the second protrusions protrude from the outer side of the second electrode plate outwardly to the first separator adjacent to the second electrode plate. 
     
     
         20 . The secondary battery of  claim 19 , wherein a height of the first protrusions is larger than a height of the second protrusions, the height of the first protrusions is less than 80 μm, and the height of the second protrusions is less than 20 μm.