System and method for quantitatively measuring gases generated by a battery cell or battery cell component as a function of time during testing

1 . A method for measuring gases generated by at least a portion of a battery cell, comprising:

arranging a test sample in a chamber,

wherein the test sample comprises:

a battery cell including terminals and a gas port; or

a test fixture including terminals and a gas port, and housing at least a portion of a battery cell;

connecting the gas port of the test sample to a node via a check valve;

connecting a gas source to the node via a pressure regulator and a flow controller;

supplying a carrier gas from the gas source to the node without passing to the chamber, the carrier gas supplied to the node via the pressure regulator and the flow controller at a regulated pressure and flow rate;

allowing gases produced by the test sample during testing to pass through the check valve when a pressure differential on opposing sides of the check valve is greater than a predetermined pressure differential;

sampling gas at or downstream from the node using at least one of a mass spectrometer and a gas analyzer, wherein the gas sampled at or downstream from the node includes the carrier gas and the gases produced by the test sample and entrained in the carrier gas; and

determining concentrations of gases in the test sample using the at least one of the mass spectrometer and the gas analyzer.

2 . The method of claim 1 , wherein the check valve includes a first port connected to the test sample and a second port connected to the node.

3 . The method of claim 1 , wherein the carrier gas is supplied at a first flow rate that is greater than or equal to ten times a second flow rate of gases produced by the test sample during testing.

4 . The method of claim 1 , wherein the carrier gas comprises a mixture of an inert gas and a reference gas with a predetermined concentration.

5 . The method of claim 4 , wherein:

the at least one of the mass spectrometer and the gas analyzer comprises the mass spectrometer, and

the mass spectrometer is calibrated with the reference gas as an internal standard.

6 . The method of claim 1 , wherein the test sample is heated to a predetermined temperature during testing.

7 . The method of claim 1 , wherein the test sample is heated based on a temperature profile as a function of time during testing.

8 . The method of claim 1 , further comprising charging the test sample to a predetermined voltage prior to testing.

9 . The method of claim 1 , further comprising at least one of supplying current to and drawing current from the test sample during testing.

10 . The method of claim 1 , further comprising sampling a voltage of the battery cell as a function of time during testing.

11 . The method of claim 1 , further comprising connecting the mass spectrometer to the node using a capillary.

12 . The method of claim 1 , further comprising purging the chamber during testing using a purge gas.

13 . The method of claim 1 , further comprising monitoring at least one of a chamber temperature, a battery cell temperature, a battery cell pressure, and a chamber pressure as a function of time during testing.

14 . A system for measuring gases in a battery cell, comprising:

a chamber including a cavity configured to receive a test sample, wherein the test sample comprises:

a battery cell including terminals and a gas port; or

a test fixture including terminals and a gas port, and housing at least a portion of a battery cell;

a check valve including a first port connected to the gas port of the test sample and a second port connected to a node, the check valve configured to open and allow gases produced by the test sample during testing to pass through when a pressure differential on opposing sides of the check valve is greater than a predetermined pressure differential;

a first gas source connected to the node via a pressure regulator and a flow controller, the first gas source configured to supply a carrier gas from the gas source to the node without passing to the chamber, the carrier gas supplied to the node via the pressure regulator and the flow controller at a regulated pressure and flow rate, the carrier gas including an inert gas and a reference gas having a predetermined concentration; and

a mass spectrometer configured to sample gas at the node and to determine a concentration of one or more gases in the battery cell as a function of time, wherein the gas sampled includes the carrier gas and the gases produced by the test sample and entrained in the carrier gas.

15 . The system of claim 14 , wherein the carrier gas is supplied at a first flow rate that is greater than or equal to ten times a second flow rate of gases produced by the test sample during testing.

16 . The system of claim 14 , wherein:

the mass spectrometer is calibrated with the reference gas as an internal standard.

17 . The system of claim 14 , further comprising a heater to one of:

heat the test sample to a predetermined temperature during testing, and

heat the test sample based on a temperature profile as a function of time during testing.

18 . The system of claim 14 , further comprising a voltage/current sensor/source configured to at least one of:

charge the test sample to a predetermined voltage prior to testing;

supply current to and drawing current from the test sample during testing; and

monitor at least one of current and voltage of the test sample as a function of time during testing.

19 . The system of claim 14 , further comprising at least one of:

a chamber pressure sensor to monitor pressure in the chamber as a function of time during testing; and

a test sample pressure sensor configured to monitor pressure in one of an enclosure of the battery cell and in the test fixture.

20 . The system of claim 14 , wherein the mass spectrometer uses vacuum to sample the gas at the node.