Battery cell refillable with electrolyte, battery pack, electrolyte refilling system for battery pack, and electrolyte refilling method for battery pack

Patent metadata

Field	Value
Publication number	US-11081765-B2
Application number	US-201816470026-A
Country	US
Kind code	B2
Filing date	Jan 23, 2018
Priority date	Jun 7, 2017
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

The present invention relates to a battery cell refillable with an electrolyte, an electrolyte refilling system for a battery pack configured to include a plurality of battery cells, and an electrolyte refilling method for a battery pack of an electric vehicle.

First claim

What is claimed is:

1. An electrolyte refilling system for a battery pack comprising:
(1) a plurality of battery cells each comprising a cell accommodating case configured to accommodate an electrode assembly comprising a negative electrode plate, a positive electrode plate, and a separator interposed between the negative electrode plate and the positive electrode plate,
wherein the cell accommodating case has, on one side thereof, a cell filling port comprising a filling valve, and has, on the other side thereof facing the cell filling port, a cell discharge port comprising a discharge valve;

(2) a battery pack in which the cell filling port of each battery cell is connected in parallel to each other through a main filling tube,
the cell discharge port of each battery cell is connected in parallel to each other through a main discharge tube,
the cell filling ports and the cell discharge ports are accommodated in an outer case, and a main filling port of the main filling tube and a main discharge port of the main discharge tube pass through the outer case and are exposed to the outside;

(3) a liquid filling pump connected to the main filling port of the main filling tube of the battery pack;
(4) a solvent tank comprising a solvent valve configured to supply or block the solvent supplied to the liquid filling pump;
(5) an electrolyte tank comprising an electrolyte valve configured to supply or block the electrolyte supplied to the liquid filling pump;
(6) an electrolyte refilling determining unit configured to calculate a 1C capacity holding rate (%) of the battery pack and determine a necessity of refilling the electrolyte;
(7) a supply amount calculating unit configured to calculate amounts of the solvent and electrolyte to be supplied to the solvent tank and the electrolyte tank;
(8) a control unit configured to control, according to the determination of the necessity of refilling the electrolyte from the electrolyte refilling determining unit, the filling valve, the discharge valve, the liquid filling pump, the solvent valve, and the electrolyte valve so as to supply the calculated amounts of solvent and electrolyte to each battery cell constituting the battery pack; and
(9) a notifying unit configured to notify a user of the necessity of refilling the electrolyte and the calculated amounts of solvent and electrolyte.

2. The electrolyte refilling system of claim 1 , wherein the battery pack further comprises a gas discharge tube on one side of the main discharge tube, wherein the gas discharge tube further comprising a gas amount measuring apparatus.

3. The electrolyte refilling system of claim 2 , wherein the gas amount measuring apparatus measures and transmits, to the supply amount calculating unit, an amount of gas discharged through the main discharge tube.

4. The electrolyte refilling system of claim 1 , wherein the 1C capacity holding rate (%) is calculated by Equation 1 below:

1
⁢
C
⁢

⁢
capacity
⁢

⁢
holding
⁢

⁢
rate
⁢

⁢

(
%
)

=

Current
⁢

⁢
1
⁢
C
⁢

⁢
discharge
⁢

⁢
capacity

Initial
⁢

⁢
1
⁢
C
⁢

⁢
discharge
⁢

⁢
capacity

×
100

(

Equation
⁢

⁢
1

)

in Equation 1, the initial 1C discharge capacity is a discharge capacity calculated when the battery pack has been manufactured, and the current 1C discharge capacity is a discharge capacity of the battery pack in use.

5. The electrolyte refilling system of claim 1 , wherein the supply amount calculating unit calculates a solvent supply amount as approximately 100% to approximately 150% of an amount of electrolyte having already been filled into the battery pack.

6. The electrolyte refilling system of claim 1 , wherein the supply amount calculating unit
measures an amount of gas discharged to the main discharge tube,
calculates, on the basis of the measured amount of gas, an amount (A) of electrolyte which has been already injected and converted into a reaction by-product due to a chemical reaction with the electrode assembly, and
calculates an electrolyte supply amount by using Equation 2 below
Electrolyte supply amount (ml)=Already filled electrolyte amount (ml)− A (ml).  (Equation 2)

7. The electrolyte refilling system of claim 1 , wherein
when the electrolyte refilling determining unit determines the refill of the electrolyte, the control unit opens the filling valves and the discharge valves of the battery cells so that a solvent supplied to the solvent tank is filled into each battery cell by the liquid filling pump and the electrolyte inside the battery cell is thereby discharged;
when the solvent is completely filled, the control unit closes the discharge valves of the battery cells and the solvent valve of the solvent tank and opens the electrolyte valve of the electrolyte tank so that the electrolyte supplied to the electrolyte tank by the liquid filling pump is filled into each battery cell and the solvent is thereby discharged; and
when the electrolyte is completely filled, the control unit closes the filling valves of the battery cells and the

Assignees

• Lg Chemical Ltd

Inventors

• Hong Chul Gi
• Lee Jae Hyun
• Kim Dong Kyu
• Kim Dae Soo

Classifications

• H01M50/691 Primary

  Arrangements or processes for draining liquids from casings; Cleaning battery or cell casings · CPC title

• H01M50/636

  Closing or sealing filling ports, e.g. using lids · CPC title

• H01M50/682 Primary

  accommodated in battery or cell casings · CPC title

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title

• H01M50/211

  adapted for pouch cells · CPC title