In-situ stress detector for an electrode and a method of use

Patent metadata

Field	Value
Publication number	US-10054501-B2
Application number	US-201615071734-A
Country	US
Kind code	B2
Filing date	Mar 16, 2016
Priority date	Mar 16, 2016
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A stress detector for detecting an in-situ stress profile of an electrode has a liquid cell, a holder configured to attach to one end of a sample electrode so that the sample electrode is cantilevered in the liquid cell, a piezo sensor comprising a piezo material in the liquid cell and having a movable end configured to contact the sample electrode and a fixed end fixedly engaged within the liquid cell and a measurement sensor in contact with the piezo sensor.

First claim

What is claimed is:

1. A stress detector for detecting an in-situ stress profile of an electrode of a battery comprising a current collector having a surface on which electrode active material is applied, the stress detector comprising:
a liquid cell;
a holder configured to attach to one end of the current collector so that the electrode is cantilevered in the liquid cell;
a piezo sensor comprising a piezo material in the liquid cell and having a movable end configured to contact the current collector at an end opposite the holder and a fixed end fixedly engaged within the liquid cell on a wall opposite the holder; and
a measurement sensor in contact with the piezo sensor.

2. The stress detector of claim 1 , wherein the measurement sensor is a voltmeter configured to measure a voltage generated from a change in shape of the piezo sensor.

3. The stress detector of claim 1 , wherein the piezo sensor is non-conductive.

4. The stress detector of claim 1 , wherein the piezo sensor is a piezo thin film.

5. The stress detector of claim 4 , wherein the piezo thin film is a polyvinylidene fluoride material.

6. The stress detector of claim 1 , wherein the measurement sensor is in contact with the movable end of the piezo sensor.

7. The stress detector of claim 1 , wherein the measurement sensor is configured to measure a movement of the piezo sensor.

8. A stress detector for detecting an in-situ stress profile of an electrode in a liquid cell representing a lithium ion battery, the stress detector comprising:
the electrode comprising a current collector having a surface on which electrode active material is applied, opposing ends of the current collector remaining uncovered;
a holder configured to attach to one end of the current collector so that the electrode is cantilevered in the liquid cell;
a piezo sensor comprising a piezo material in the liquid cell and having a movable end configured to contact the current collector at an end opposite the holder and a fixed end fixedly engaged within the liquid cell;
a measurement sensor in contact with the piezo sensor;
a separator spaced from the electrode active material opposite the current collector;
lithium metal spaced from the separator opposite the electrode active material; and
electrolyte filling the liquid cell.

9. A method for in-situ detection of a stress profile of an electrode, the method comprising:
suspending the electrode in a liquid cell comprising a piezo sensor, the electrode comprising a current collector having a surface on which electrode active material is applied, opposing ends of the current collector remaining uncovered, by:
attaching a fixed end of the current collector to the liquid cell; and
contacting a movable end of the current collector opposite the fixed end with a movable end of the piezo sensor, wherein the piezo sensor is fixedly attached at an opposite end to the liquid cell;

cycling the liquid cell through charge and discharge;
measuring a movement of the movable end of the piezo sensor with a measurement meter.

10. The method of claim 9 , wherein the measurement sensor is a voltmeter that measures a voltage generated from a change in shape of the piezo sensor.

11. The method of claim 9 , wherein the piezo sensor is non-conductive.

12. The method of claim 9 , wherein the piezo sensor is a piezo thin film.

13. The method of claim 12 , wherein the piezo thin film is a polyvinylidene fluoride material.

14. The method of claim 9 , wherein the liquid cell represents a lithium ion battery, the liquid cell comprising:
a separator spaced from the electrode active material opposite the current collector;
lithium metal spaced from the separator opposite the electrode active material; and
electrolyte filling the liquid cell.

15. The method of claim 9 , wherein the measurement sensor is in contact with the movable end of the piezo sensor.

16. The method of claim 9 , wherein the fixed end of the piezo sensor is attached to a wall of the liquid cell.

17. The method of claim 16 , wherein the fixed end of the current collector is attached to a wall of the liquid cell opposite the fixed end of the piezo sensor.

Assignees

• Nissan North America Inc

Inventors

• Liu Ying
• Oshihara Kenzo

Classifications

• G01R31/68

  Testing of releasable connections, e.g. of terminals mounted on a printed circuit board · CPC title

• H01M10/4285 Primary

  Testing apparatus · CPC title

• G01R31/016

  Testing of capacitors (measuring capacitance G01R27/2605) · CPC title

• H01M10/0525

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

• G01L1/16 Primary

  using properties of piezoelectric devices · CPC title