Electrode assembly and polymer secondary battery cell including the same

Patent metadata

Field	Value
Publication number	US-10615392-B2
Application number	US-201815914624-A
Country	US
Kind code	B2
Filing date	Mar 7, 2018
Priority date	Feb 15, 2013
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

An electrode assembly includes a cell stack part having a structure of steps obtained by stacking at least two groups of radical units having different sizes or having different geometric shapes according to the size or the geometric shapes. The radical unit has a combined structure into one body by alternately disposing same number of electrodes and separators, and each step of the cell stack part has a structure in which one kind of radical units is disposed once or repeatedly, or a structure in which at least two kinds of radical units are disposed. The one kind of radical unit has a four-layered structure of first electrode, first separator, second electrode and second separator sequentially stacked or a repeating structure of the four-layered structure. Each of the at least two kinds of radical units are stacked by ones to form the four-layered structure or the repeating structure.

First claim

What is claimed is:

1. An electrode assembly, comprising:
a cell stack part having a structure of a plurality of steps obtained by stacking radical units according to a size or geometric shape thereof, the radical units being classified into at least two groups having different sizes or geometric shapes; and
a fixing part for fixing the cell stack part,
wherein the radical unit has a same number of electrodes and separators which are alternately disposed and integrally combined,
wherein each step of the cell stack part has (a) a structure in which one kind of radical unit is disposed once or repeatedly or (b) a structure in which at least two kinds of radical units are disposed in a predetermined order,
wherein the one kind of radical unit of (a) has a four-layered structure in which a first electrode, a first separator, a second electrode and a second separator are sequentially stacked together or a repeating structure in which the four-layered structure is repeatedly stacked,
wherein each of the at least two kinds of radical units of (b) are stacked by ones in the predetermined order to form the four-layered structure or the repeating structure in which the four-layered structure is repeatedly stacked,
wherein the fixing part is adhered to one or more steps of the plurality of steps of the cell stack part, and
wherein a portion of an outermost electrode of the cell stack part is covered by the fixing part and a portion of the outermost electrode of the cell stack part is not covered by the fixing part.

2. The electrode assembly of claim 1 , wherein edge of the separator is not joined with edge of an adjacent separator.

3. The electrode assembly of claim 1 , wherein adjacent radical units are not combined with each other in the cell stack part, or are combined with each other in the cell stack part with a combining strength differing from a combining strength between the electrode and the separator in the radical unit.

4. The electrode assembly of claim 1 ,
wherein the one kind of radical unit of (a) comprises a first radical unit having the four-layered structure or the repeating structure in which the four-layered structure is repeatedly stacked, and
wherein each step of the cell stack part has a structure obtained by disposing the first radical units once or repeatedly.

5. The electrode assembly of claim 1 ,
wherein the at least two kinds of radical units of (b) comprises:
a second radical unit having the first electrode, the first separator, the second electrode, the second separator, the first electrode, and the first separator, which are sequentially disposed and integrally combined; and
a third radical unit having the second electrode, the second separator, the first electrode, the first separator, the second electrode, and the second separator, which are sequentially disposed and integrally combined, and
wherein the cell stack part has a structure in which the second radical unit and the third radical unit are alternately disposed.

6. The electrode assembly of claim 1 , wherein the electrode is attached to an adjacent separator in each radical unit.

7. The electrode assembly of claim 6 , wherein an entire surface of the electrode facing the adjacent separator is attached to the adjacent separator.

8. The electrode assembly of claim 6 , wherein the attachment between the electrode and the separator is provided by applying pressure to the electrode and the adjacent separator or by applying pressure and heat to the electrode and the adjacent separator.

9. The electrode assembly of claim 6 , wherein adhesive strength between the electrode and the adjacent separator in the radical unit is greater than adhesive strength between the radical units in the cell stack part.

10. The electrode assembly of claim 6 ,
wherein the separator comprises a porous separator base material and a porous coating layer that is applied to an entire surface of one side or both sides of the separator base material,
wherein the porous coating layer comprises a mixture of inorganic particles and a binder polymer, wherein the binder polymer binds and fixes the inorganic particles to each other, and
wherein the electrode is attached to the adjacent separator by the coating layer.

11. The electrode assembly of claim 10 ,
wherein the inorganic particles of the porous coating layer have a densely packed structure to form interstitial volumes between the inorganic particles over the overall coating layer, and
wherein a pore structure is formed in the coating layer by the interstitial volumes that are defined by the inorganic particles.

12. The electrode assembly of claim 1 ,
wherein the cell stack part further comprises a first auxiliary unit stacked on a terminal electrode that is an uppermost or a lowermost electrode,
wherein, when the terminal electrode is a cathode, the first auxiliary unit is formed by stacking from the terminal electrode, a separator, an anode, a separator, and a cathode in sequence, and
wherein, when the terminal electrode is an anode, the first auxiliary unit is formed by stacking from the terminal electrode, a separator and a cathode in sequence.

13. The electrode assembly of claim 12 , wherein the cathode of the first auxiliary unit comprises:
a current collector; and
an active material coated on only one side facing the radical unit among both sides of the current collector.

14. The electrode assembly of claim 1 ,
wherein the cell stack part further comprises a second auxiliary unit on a terminal separator that is an uppermost or a lowermost separator,
wherein, when the electrode contacting the terminal separator is a cathode in the radical unit, the second auxiliary unit is formed by stacking from the terminal separator, an anode, a separator and a cathode in sequence, and
wherein, when the electrode contacting the terminal separator is an anode in the radical unit, the second auxiliary unit is formed as a cathode.

15. The electrode assembly of claim 14 , wherein the cathode of the second auxiliary unit comprises:
a current collector; and
an active material coated on only one side facing the radical unit among both sides of the current collector.

16. The electrode assembly of claim 1 ,
wherein the cell stack part further comprises a first auxiliary unit stacked on a terminal electrode disposed on an uppermost or a lowermost electrode,
wherein, when the terminal electrode is a cathode, the first auxiliary unit is formed by stacking from the terminal electrode, a separator and an anode in sequence, and
wherein, when the terminal electrode is an anode, the first auxiliary unit is formed by stacking from the terminal electrode, a separator, a cathode, a separator and an anode in sequence.

17. The electrode assembly of claim 16 , wherein the first auxiliary unit further comprises a separator at an outer side of the anode.

18. The electrode assembly of claim 1 ,
wherein the cell stack part further comprises a second auxiliary unit on a terminal separator that is an uppermost or a lowermost separator,
wherein, when the electrode contacting the terminal separator is a cathode in the radical unit, the second auxiliary unit is formed as an anode, and
wherein, when the electrode contacting the terminal separator is an anode in the radical unit, the second auxiliary unit is formed by stacking from the terminal separator, a cathode, a separator, and an anode in sequence.

19. The electrode assembly of claim 18 , wherein the second auxiliary unit further comprises a separator at an outer side of the

Assignees

• Lg Chemical Ltd

Inventors

• Park Ji Won
• Ko Myung Hoon
• Na Seung Ho
• Ahn Chang Bum

Classifications

• H01M10/0468

  Compression means for stacks of electrodes and separators · CPC title

• H01M10/0413 Primary

  Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes · CPC title

• H01M10/0585 Primary

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title

• H01M10/0565

  Polymeric materials, e.g. gel-type or solid-type · CPC title

• H01M10/0436 Primary

  Small-sized flat cells or batteries for portable equipment · CPC title