Electrode assembly, secondary battery, and method of manufacture
A secondary battery for cycling between a charged and a discharged state, comprises a battery enclosure, an electrode assembly, carrier ions, and an electrolyte, wherein the electrode assembly comprises a population of unit cells, each unit cell comprising, in a stacking direction, a unit cell portion of an electrode current collector layer, an electrode layer comprising electrode active material, a separator layer, a counter-electrode layer and a unit cell portion of a counter-electrode current collector layer, and a subset of the members of the unit cell population comprises a population of spacer structures located in the stacked succession, and for each member of unit cell population subset there exists an imaginary line that extends in a direction that is orthogonal to the stacking direction and intersects the counter-electrode layer and at least one member of the spacer structure population comprised by each respective member of the unit cell population subset.
1 . A unit cell for a secondary battery, the unit cell comprising, in a stacking direction, a unit cell portion of an electrode current collector layer, an electrode layer comprising electrode active material, a separator layer, a counter-electrode layer and a unit cell portion of a counter-electrode current collector layer,
wherein the unit cell has a width, W uc , measured in the stacking direction of the stacked succession from the unit cell portion of the electrode current collector layer to the unit cell portion of the counter-electrode current collector layer,
wherein the electrode layer has:
a width, W E , measured in the stacking direction of the stacked succession, from the unit cell portion of the electrode current collector layer adjacent the electrode layer to the separator layer adjacent the electrode layer,
a height, H E , measured in a direction parallel to a vertical axis of the unit cell from a top surface to a bottom surface of the electrode layer, the vertical axis oriented in a second direction orthogonal to the stacking direction, and
a length, L E , measured from a first surface to a second surface;
wherein the counter-electrode layer has:
a width, W CE , measured in the stacking direction, from the unit cell portion of the counter-electrode current collector layer adjacent the counter-electrode layer to the separator layer adjacent the counter-electrode layer,
a height, H CE , measured in a direction parallel to the vertical axis of the unit cell from a top surface to a bottom surface of the counter-electrode layer, and
a length, L CE , measured from a first surface to a second surface;
wherein the unit cell comprises a spacer structure located in the stacked succession between the electrode current collector layer and the counter-electrode current collector layer, the spacer structure comprising a material other than the electrode active material; and
wherein there exists a first imaginary line that extends in a direction that is orthogonal to the stacking direction and intersects the counter-electrode layer, the separator layer, and the spacer structure and there exists a second imaginary line that extends in the direction that is orthogonal to the stacking direction and intersects the counter-electrode layer and the separator layer but does not intersect the spacer structures.
2 . An electrode assembly comprising a population of unit cells wherein for each unit cell:
the unit cell comprises, in a stacking direction, a unit cell portion of an electrode current collector layer, an electrode layer comprising electrode active material, a separator layer, a counter-electrode layer and a unit cell portion of a counter-electrode current collector layer, an order of stacking of the unit cell portion of the electrode current collector layer, the electrode layer, the separator layer, the counter-electrode layer, and the unit cell portion of the counter-electrode current collector layer of the unit cell is reversed relative to an order of stacking of an adjacent unit cell,
the unit cell has a width, W uc , measured in the stacking direction of the stacked succession from the unit cell portion of the electrode current collector layer to the unit cell portion of the counter-electrode current collector layer, the electrode layer of the unit cell having:
a width, W E , measured in the stacking direction of the stacked succession, from the unit cell portion of the electrode current collector layer adjacent the electrode layer to the separator layer adjacent the electrode layer,
a height, H E , measured in a direction parallel to a vertical axis of the unit cell from a top surface to a bottom surface of the electrode layer, the vertical axis oriented in a second direction orthogonal to the stacking direction, and
a length, L E , measured from a first surface to a second surface; and
the counter-electrode layer of the unit cell having: a width, W CE , measured in the stacking direction, from the unit cell portion of the counter-electrode current collector layer adjacent the counter-electrode layer to the separator layer adjacent the counter-electrode layer,
a height, H CE , measured in a direction parallel to the vertical axis of the unit cell from a top surface to a bottom surface of the counter-electrode layer, and a length, L CE , measured from a first surface to a second surface, and wherein a subset of the members of the population of unit cells comprises a population of spacer structures located in the stacked succession between the electrode current collector layer and the counter-electrode current collector layer, the spacer structures comprising a material other than the electrode active material;
wherein each member of the subset of the population of unit cells comprises at least one member of the population of spacer structures; and wherein, for each respective member of the subset of the population of unit cells, there exists a first imaginary line that extends in a direction that is orthogonal to the stacking direction and intersects the counter-electrode layer, the separator layer, and the at least one member of the population of spacer structures comprised by each respective member of the unit cell population subset, and there exists a second imaginary line that extends in the direction that is orthogonal to the stacking direction and intersects the counter-electrode layer and the separator layer, but does not intersect the spacer structures.
3 . A secondary battery for cycling between a charged and a discharged state, the secondary battery comprising a battery enclosure, an electrode assembly comprising a population of unit cells, carrier ions, and an electrolyte within the battery enclosure, wherein for each unit cell: the unit cell comprises, in a stacking direction, a unit cell portion of an electrode current collector layer, an electrode layer comprising electrode active material, a separator layer, a counter-electrode layer and a unit cell portion of a counter-electrode current collector layer, the order of stacking of the unit cell portion of the electrode current collector layer, the electrode layer, the separator layer, the counter-electrode layer, and the unit cell portion of the counter-electrode current collector layer of the unit cell being reversed relative to an order of stacking of an adjacent unit cell, the unit cell has a width, W uc , measured in the stacking direction of the stacked succession from the unit cell portion of the electrode current collector layer to the unit cell portion of the counter-electrode current collector layer,
the electrode layer of the unit cell having: a width, W E , measured in the stacking direction of the stacked succession, from the unit cell portion of the electrode current collector layer adjacent the electrode layer to the separator layer adjacent the electrode layer,
a height, H E , measured in a direction parallel to a vertical axis of the unit cell from a top surface to a bottom surface of the electrode layer, the vertical axis oriented in a second direction orthogonal to the stacking direction, and
a length, L E , measured from a first surface to a second surface; and the counter-electrode layer of the unit cell having: a width, W CE , measured in the stacking direction, from the unit cell portion of the counter-electrode current collector layer adjacent the counter-electrode layer to the separator layer adjacent the counter-electrode layer,
a height, H CE , measured in a direction parallel to the vertical axis of the unit cell from a top surface to a bottom surface of the counter-electrode layer, and a length, L CE , measured a first surface to a second surface,
wherein a subset of the members of the population of unit cells comprises a population of spacer structures located in the stacked succession between the electrode current collector layer and the counter-electrode current collector layer, the popluation of spacer structures comprising a material other than the electrode active material;
wherein each member of the subset of the population of unit cells comprises at least one member of the population of spacer structures; and wherein, for each respective member of the subset of the population of unit cells, there exists a first imaginary line that extends in a direction that is orthogonal to the stacking direction and intersects the counter-electrode layer, the separator layer, and the at least one member of the population of spacer structures comprised by each respective member of the unit cell population subset, and there exists a second imaginary line that extends in the direction that is orthogonal to the stacking direction and intersects the counter-electrode layer and the separator layer but does not intersect the at least one member of the population of spacer structures.
4 . The secondary battery of claim 3 , wherein the electrode assembly is a wound electrode assembly.
5 . The secondary battery of claim 4 , wherein the population of spacer structures comprises a plurality of bands that extend along the length, L E , of a wound electrode layer through multiple winds.
6 . The secondary battery of claim 4 , wherein the population of spacer structures comprises a plurality of bands at multiple different locations along the length, L E , of a wound electrode layer that extend along the height, H E , of the wound electrode layer.
7 . The secondary battery of claim 3 , further comprising a series of stacked sheets comprising the electrode layer and counter-electrode layer, where the stacking direction is in a first direction, the height, H E , of the electrode layer is measured in a second direction orthogonal to the stacking direction, the length, L E , of the electrode layer is measured in a third direction orthogonal to both the second direction and stacking direction, and the first imaginary line extends in the second direction.
8 . The secondary battery of claim 4 , wherein the wound electrode assembly comprises at least one electrode layer that is continuously wound about an interior region, with a distance between the electrode layer and the interior region increasing with each successive wind about the interior region, and wherein the stacked succession of unit cells in the wound electrode assembly comprises a population of inner unit cells located in one or more inner winds of the electrode assembly, and a population of outer unit cells located in one or more outer winds of the electrode assembly, with the population of inner and outer unit cells in the stacked succession being aligned with one another in the stacking direction.
9 . The secondary battery of claim 3 , wherein within the members of the unit cell population the width, W E , of the electrode layer and the width, W CE , of the counter-electrode layer are measured in the stacking direction of the stacked succession, the height, H E , of the electrode layer and the height, H CE , of the counter-electrode layer are measured in the second direction orthogonal to the stacking direction, and the length, L E , of the electrode layer and the length, L CE , of the counter-electrode layer are measured along the longest dimension of the electrode layer and counter-electrode layer that corresponds to a wound path of the electrode layer and counter-electrode layer, respectively, from an interior region of the electrode assembly to an exterior region of the electrode assembly.
10 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset have a width, W SP , that extends in the stacking direction across: at least 50% of the width, W CE , of the counter-electrode layer; at least 60% of the width, W CE , of the counter-electrode layer; at least 70% of the width, W CE , of the counter-electrode layer; at least 80% of the width, W CE , of the counter-electrode layer; at least 90% of the width, W CE , of the counter-electrode layer; at least 95% of the width, W CE , of the counter-electrode layer; at least 98% of the width, W CE , of the counter-electrode layer; and/or at least 99% of the width, W CE , of the counter-electrode layer.
11 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset have a width, W SP , in the stacking direction that extends from a surface of the unit cell portion of the electrode current collector layer facing the counter-electrode layer, to a region laterally adjacent to or surrounded by the counter-electrode layer.
12 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset extend in the stacking direction to a surface of the separator layer facing the unit cell portion of the electrode current collector layer.
13 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset comprises a pair of spacer structures that at least partially cover the top surface and the bottom surface of the counter-electrode layer of the members of the unit cell population subset.
14 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset comprises one or more spacer structures that extend through a width, W CE , of the counter-electrode layer of the members of the unit cell population subset.
15 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset comprises a pair of spacer structures that are spaced apart from one another along the length, L E , of the electrode layer of the members of the unit cell population subset.
16 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset comprises a pair of spacer structures that are spaced apart from one another along the height, H E , of the electrode layer of the members of the unit cell population subset.
17 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset comprises one or more spacer structures that extend along the height, H E , of the electrode layer of the members of the unit cell population subset.
18 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset comprises a plurality of bands of spacer material that extend along the length, L E , of the electrode layer of the members of the unit cell population subset, and at a plurality of different vertical locations along the height, H E , of the electrode layer(s) of the members of the unit cell population subset.
19 . The secondary battery of claim 3 , wherein the secondary battery comprises a wound electrode layer, and wherein a plurality of bands of spacer material that extend along the length, L E , of the wound electrode layer through multiple winds.
20 . The secondary battery of claim 3 , wherein the population of spacer structures within the members of the unit cell population subset comprises a plurality of bands of spacer material that extend along the height, H E , of the electrode layer of the members of the unit cell population subset, and at a plurality of different locations along the length, L E , of the electrode layer(s) of the members of the unit cell population subset.