Electrode assembly, secondary battery, and method of manufacture

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, Wuc, 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, WE, 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, HE, 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, LE, measured from a first surface to a second surface;
• and
• the counter-electrode layer of the unit cell having:
• a width, WCE, 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, HCE, 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, LCE, 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.

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, Wuc, 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, WE, 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, HE, 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, LE, measured from a first surface to a second surface;
• and the counter-electrode layer of the unit cell having:
• a width, WCE, 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, HCE, 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, LCE, 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.