Magnetic force dilatometer for measuring dilation of individual electrode
A dilatometer for measuring battery dilation including: a battery cell with a first electrode and a second electrode; an internal magnetic sensing element; and a magnetic force sensor. The internal magnetic sensing element is configured to move in response to expansion the first electrode and remain stationary in response to expansion of the second electrode during dilation of the battery cell. The magnetic force sensor is stationary relative to the battery cell and configured to sense a change in magnetic force strength between the internal magnetic sensing element and the magnetic force sensor. A controller is configured to measure dilation of the first electrode independent of dilation of the second electrode based on the change in the magnetic force strength between the internal magnetic sensing element and the magnetic force sensor.
1 . A dilatometer for measuring battery dilation comprising:
a battery cell including a first electrode and a second electrode;
an internal magnetic sensing element;
a magnetic force sensor,
wherein the internal magnetic sensing element is configured to move in response to expansion of the first electrode and remain stationary in response to expansion of the second electrode during dilation of the battery cell, and the magnetic force sensor is stationary relative to the battery cell,
wherein the magnetic force sensor is configured to sense a change in magnetic force strength between the internal magnetic sensing element and the magnetic force sensor; and
a controller configured to measure dilation of the first electrode independent of dilation of the second electrode based on the change in the magnetic force strength between the internal magnetic sensing element and the magnetic force sensor.
2 . The dilatometer of claim 1 , wherein the internal magnetic sensing element is between the first electrode and the second electrode.
3 . The dilatometer of claim 1 , wherein the battery cell further includes a separator between the first electrode and the second electrode, the internal magnetic sensing element is between a first portion of the separator and a second portion of the separator.
4 . The dilatometer of claim 1 , wherein the first electrode is closer to the magnetic force sensor than the second electrode.
5 . The dilatometer of claim 1 , wherein the internal magnetic sensing element is configured to allow ions to pass across the internal magnetic sensing element to move between the first electrode and the second electrode.
6 . The dilatometer of claim 5 , wherein the internal magnetic sensing element is porous and configured to allow an electrolyte of the battery cell to extend through the internal magnetic sensing element.
7 . The dilatometer of claim 5 , wherein the internal magnetic sensing element is coated with a nonconductive material.
8 . The dilatometer of claim 1 , further comprising a support between the first electrode and the second electrode, the support supporting the first electrode and configured to permit ions to pass across the support to move between the first electrode and the second electrode.
9 . The dilatometer of claim 8 , wherein the internal magnetic sensing element is arranged adjacent to the first electrode and configured to move away from the magnetic force sensor as the first electrode expands during dilation and remain stationary as the second electrode expands during dilation.
10 . The dilatometer of claim 1 , wherein the magnetic force sensor further includes one of a load sensor, a strain gauge, a pressure sensor, and an electromagnetic force restoration sensor.
11 . The dilatometer of claim 1 , wherein the battery cell is a pouch cell.
12 . The dilatometer of claim 1 , wherein the battery cell is a prismatic cell.
13 . A dilatometer for measuring dilation in a coin cell battery, the dilatometer comprising:
a housing of the coin cell battery;
a first electrode within the housing;
a second electrode within the housing;
a separator in the housing between the first electrode and the second electrode;
an internal magnetic sensing element within the housing configured to move in response to expansion of the first electrode and remain stationary in response to expansion of the second electrode during dilation of the coin cell battery;
an external magnet outside of the housing and spaced from the housing;
a sensor configured to measure magnetic force strength between the internal magnetic sensing element and the external magnet; and
a controller configured to measure dilation of the first electrode independent of dilation of the second electrode based on change in the magnetic force strength measured by the sensor between the external magnet and the internal magnetic sensing element.
14 . The dilatometer of claim 13 , wherein the internal magnetic sensing element is between a first portion of the separator and a second portion of the separator.
15 . The dilatometer of claim 13 , further comprising a support member between a first portion of the separator and a second portion of the separator, the support member supporting the first electrode and configured to permit ions to pass across the support to move between the first electrode and the second electrode.
16 . The dilatometer of claim 15 , wherein the internal magnetic sensing element is arranged adjacent to the first electrode and configured to move away from the sensor as the first electrode expands during dilation and remain stationary as the second electrode expands during dilation, the internal magnetic sensing element further configured as a spacer between the first electrode and a biasing member.
17 . A dilatometer for measuring dilation of a first electrode of a coin cell battery including the first electrode and a second electrode, the dilatometer comprising:
a coin cell holder configured to hold the coin cell battery;
an external magnet arranged adjacent to the coin cell holder and spaced from the coin cell battery seated in the coin cell holder;
a force sensor configured to measure magnetic force strength between the external magnet and an internal magnetic sensing element in the coin cell battery, the internal magnetic sensing element configured to move in response to expansion of the first electrode and remain stationary in response to expansion of the second electrode during dilation of the coin cell battery;
a translation stage configured to support the force sensor; and
a controller configured to measure dilation of the first electrode independent of dilation of the second electrode based on change in the magnetic force strength measured by the force sensor between the external magnet and the internal magnetic sensing element.
18 . The dilatometer of claim 17 , wherein the external magnet is one of a spherical magnet, a hemispherical magnet, and a conical magnet.
19 . The dilatometer of claim 17 , wherein the force sensor includes one of a load cell, a strain gauge, and a pressure sensor.
20 . The dilatometer of claim 17 , wherein:
the coin cell holder is configured to hold the coin cell battery during at least one of charging and discharging of the coin cell battery; and
wherein the controller is configured to measure dilation of the first electrode independent of the second electrode during the at least one of charging and discharging of the coin cell battery.