Charging device and charging method

Patent metadata

Field	Value
Publication number	US-11545847-B2
Application number	US-202016774817-A
Country	US
Kind code	B2
Filing date	Jan 28, 2020
Priority date	Jul 28, 2017
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

A charging device for charging a lithium-ion secondary battery based on at least a constant voltage method is provided. In the charging device, before starting charging with a constant voltage or while performing charging with a constant voltage, a first current pulse having a peak current value i1 larger than a charge current value i0 is applied at least once.

First claim

The invention claimed is:

1. A charging device for charging a lithium-ion secondary battery based on at least a constant voltage method,
wherein, before starting charging with a constant voltage or while performing charging with a constant voltage, a first current pulse having a peak current value i 1 larger than a charge current value i 0 is applied at least once, and
wherein
the lithium-ion secondary battery is charged based on a constant current-constant voltage method, and
a second current pulse is applied before starting charging with the constant voltage after completing charging with a constant current.

2. The charging device according to claim 1 , wherein charging is configured to be performed without interruption.

3. The charging device according to claim 1 , wherein 1<i 1 /i 0 ≤10 is satisfied.

4. The charging device according to claim 1 , wherein a time during which the first current pulse is applied is 0.01 seconds or more and 10 seconds or less.

5. The charging device according to claim 1 , wherein the number of times of application of the first current pulse is one.

6. The charging device according to claim 1 , wherein, an impedance of the lithium-ion secondary battery and a charging end set current value when ending charging with the constant voltage after applying the first current pulse are Z A and I comp-A ,
an impedance of the lithium-ion secondary battery and a charging end set current value when ending charging with the constant voltage in a case where no first current pulse is applied are Z B and I comp-B , and
wherein I comp-A =(Z B /Z A )×I comp-B is satisfied.

7. The charging device according to claim 1 , wherein, a charging end set current value when ending charging with the constant voltage after applying the current pulse is I comp-A ,
a charging end set current value when ending charging with the constant voltage in a case where no first current pulse is applied is I comp-B , and
wherein I comp-B <I comp-A ≤5×I comp-B is satisfied.

8. The charging device according to claim 1 , wherein, a charging end set time when ending charging with the constant voltage after applying the current pulse is t comp-A ,
a charging end set time when ending charging with the constant voltage in a case where no first current pulse is applied is t comp-B , and
wherein 0.7×t comp-B ≤t comp-A <t comp-B is satisfied.

9. The charging device according to claim 1 , wherein the lithium-ion secondary battery includes a positive electrode material,
wherein a first crystal structure of the positive electrode material in a case that the lithium-ion secondary battery is fully charged is different from a second crystal structure of the positive electrode material in a case that the lithium-ion secondary battery is fully discharged, and
wherein a change between the first and second crystal structures of the positive electrode material according to charging and discharging is reversible.

10. The charging device according to claim 1 , wherein the positive electrode material of the lithium-ion secondary battery includes Li x CoO 2 .

11. A charging device for charging a lithium-ion secondary battery, in which a positive electrode material includes Li x CoO 2 , based on at least a constant voltage method, the device comprising:
an x value calculator configured to calculate a value of x during charging of the lithium-ion secondary battery; and
a temperature detector configured to measure a temperature of the positive electrode material during charging of the lithium-ion secondary battery,
wherein a point in time, at which a first current pulse having a peak current value i 1 larger than a charge current value i 0 immediately before applying the first current pulse is applied at least once, is determined based on the value of x calculated by the x value calculator and a value of the temperature of the positive electrode material measured by the temperature detector.

12. A charging method for charging a lithium-ion secondary battery by the charging device according to claim 11 .

13. A charging method for charging a lithium-ion secondary battery based on at least a constant voltage method, the method comprising: before starting charging with a constant voltage or while performing charging with a constant voltage, applying a first current pulse having a peak current value ii larger than a charge current value i 0 at least once,
wherein
the lithium-ion secondary battery is charged based on a constant current-constant voltage method, and
a second current pulse is applied before starting charging with the constant voltage after completing charging with a constant current.

Assignees

• Murata Manufacturing Co

Inventors

• Shimura Jusuke

Classifications

• H01M10/486

  for measuring temperature · CPC title

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/44

  Methods for charging or discharging (circuits for charging H02J7/00) · CPC title

• H01M10/0561

  the electrolyte being constituted of inorganic materials only · CPC title

• H01M10/443

  in response to temperature · CPC title