Method for prelithiation, method for fabricating lithium secondary battery comprising the method, and lithium secondary battery fabricated from the fabricating method

Patent metadata

Field	Value
Publication number	US-9705154-B2
Application number	US-201414504529-A
Country	US
Kind code	B2
Filing date	Oct 2, 2014
Priority date	Mar 11, 2013
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

The present disclosure relates to a method for prelithiation, and in particular, to a method for prelithiation that predopes lithium into at least one unit cell uniformly in large amounts. According to an aspect of the present disclosure, there is provided a method for prelithiation including an preparing at least one unit cell, the unit cell comprising a cathode, an anode, and a separator interposed between the cathode and the anode, disposing the prepared at least one unit cell in a reaction tank, and connecting electrodes having the same polarity, adding an electrolyte solution into the reaction tank, disposing a lithium metal plate in the electrolyte solution, and connecting the lithium metal plate to the anode, and doping the anode.

First claim

What is claimed is:

1. A method for prelithiation, comprising:
preparing at least one unit cell, the unit cell comprising a cathode, an anode, and a separator interposed between the cathode and the anode;
disposing the prepared at least one unit cell in a first one of a plurality of sections of a reaction tank, and connecting electrodes having the same polarity, the sections being defined within the reaction tank by at least one support partition wall positioned inside the reaction tank to separate the sections;
adding an electrolyte solution into the reaction tank;
disposing a lithium metal plate in the electrolyte solution, and forming a direct electrical connection between the lithium metal plate and the anode without forming a direct electrical connection between the lithium metal plate and the cathode, the direct electrical connection being established by a conductor selected from the group consisting of a conducting line, a wire, and a cable; and
doping the anode.

2. The method for prelithiation according to claim 1 , wherein the unit cell comprises a cathode lead and an anode lead connected to the cathode and the anode independently through a cathode tab and an anode tab, respectively, and each of the cathode lead and the anode lead is connected for the electrodes having the same polarity, independently.

3. The method for prelithiation according to claim 1 , wherein the unit cell has at least one unit cell structure in which a separator is interposed between electrodes of opposite polarity, with two outermost electrodes having opposite polarity, or at least one unit cell structure in which a separator is interposed between electrodes of opposite polarity, with two outermost electrodes having the same polarity.

4. The method for prelithiation according to claim 1 , wherein the support partition wall electrochemically isolates the first section from a second one of the sections inside of the reaction tank.

5. The method for prelithiation according to claim 1 , wherein the connection of the electrodes having the same polarity is established by a conducting line, a wire, or a cable.

6. The method for prelithiation according to claim 1 , wherein the electrolyte solution includes a lithium salt.

7. The method for prelithiation according to claim 6 , wherein the lithium salt includes a Li + ion, and an anion including F − , Cl − , Br − , I − , NO 3 − , BF 4 − , PF 6 − , N(CN) 2 − , SCN, ClO 4 − , AsF 6 − , CF 3 SO 3 − , (CF 3 SO 2 ) 2 − , C(CF 2 SO 2 ) 3 − , (CF 3 ) 3 PF 3 − , (CF 3 ) 4 PF 2 − , (CF 3 ) 5 PF − , (CF 3 ) 6 P − , (CF 3 CF 2 SO 2 − ) 2 N, (CF 3 SO 2 ) 2 N − , CF 3 SO 3 − , CF 3 CF 2 (CF 3 ) 2 CO − , (CF 3 SO 2 ) 2 CH − , (CF 3 SO 2 ) 3 C − , CF 3 (CF 2 ) 7 SO 3 − , CF 3 CO 2 − , CH 3 CO 2 − , or combinations thereof.

8. The method for prelithiation according to claim 1 , wherein the connection of the lithium metal plate to the anode is established by a conducting line, a wire, or a cable.

9. The method for prelithiation according to claim 1 , where the doping of the anode is performed such that an amount of lithium exceeding an initial irreversible capacity of the anode is doped into the anode.

10. The method for prelithiation according to claim 1 , wherein the doping of the anode comprises polarizing the anode.

11. The method for prelithiation according to claim 1 , wherein the doping of the anode is promoted by charging with such applied voltage that a voltage level of the anode is defined less than or equal to 0.05V.

12. The method for prelithiation according to claim 1 , wherein the doping of the anode is promoted by applying voltage from 3.0 to 4.6V.

13. The method for prelithiation according to claim 1 , wherein the doping of the anode is promoted by heating the reaction tank.

14. The method for prelithiation according to claim 13 , wherein the heating temperature of the reaction tank is from 25 to 100° C.

15. The method for prelithiation according to claim 14 , wherein the heating temperature of the reaction tank is from 35 to 60° C.

16. A method for fabricating a lithium secondary battery comprising the method for prelithiation according to claim 1 .

17. A lithium secondary battery fabricated by the method for fabricating a lithium secondary battery according to claim 16 .

18. The method for prelithiation according to claim 1 , wherein the support partition wall is configured such that lithium from a lithium source within a second one of the sections inside of the reaction tank can be supplied to the first section to cover a lithium shortage by the lithium metal plate in the first section.

19. The method for prelithiation according to claim 1 , wherein the step of disposing the lithium metal plate in the electrolyte solution comprises disposing the lithium metal plate in the electrolyte solution in the first section, the method further comprising disposing a lithium source in a second one of the plurality of sections of the reaction tank, the second section being separated from the first section by the support partition wall.

Assignees

• Lg Chemical Ltd

Inventors

• Lee Sang-Kyun
• Choi Bok-Kyu
• Lee Byoung-Bae
• Jeong Bong-Hyun
• Kim Kyoung-Ho
• Kim Jang-Bae

Classifications

• H01M10/4242

  Regeneration of electrolyte or reactants · CPC title

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M10/446

  Initial charging measures · CPC title

• H01M10/058

  Construction or manufacture · CPC title

• Y10T29/49108

  Electric battery cell making · CPC title