Constrained electrode assembly

A secondary battery for cycling between a charged and a discharged state, the secondary battery comprising a battery enclosure and an electrode assembly, carrier ions, a set of electrode constraints, populations of first and second insulating layers, and electrode and counter-electrode busbars for collecting current from the electrode assembly within the battery enclosure, wherein:

• (a) the electrode assembly has mutually perpendicular transverse, longitudinal and vertical axes corresponding to the x, y and z axes, respectively, of an imaginary three-dimensional cartesian coordinate system, a first longitudinal end surface and a second longitudinal end surface separated from each other in the longitudinal direction, and a lateral surface surrounding an electrode assembly longitudinal axis AEA and connecting the first and second longitudinal end surfaces, the lateral surface having opposing first and second regions on opposite sides of the longitudinal axis and separated in a first direction that is orthogonal to the longitudinal axis, the electrode assembly having a maximum width WEA measured in the longitudinal direction, a maximum length LEA bounded by the lateral surface and measured in the transverse direction, and a maximum height HEA bounded by the lateral surface and measured in the vertical direction,
• (b) the electrode assembly further comprises a population of electrode structures, a population of electrode current collectors, a population of separators that are ionically permeable to carrier ions, a population of counter-electrode structures, a population of counter-electrode current collectors, and a population of unit cells wherein
• (i) members of the electrode and counter-electrode structure populations are arranged in an alternating sequence in the longitudinal direction,
• (ii) each member of the population of electrode structures comprises a layer of an electrode active material having a length LE that corresponds to the Feret diameter of the electrode active material layer as measured in the transverse direction between first and second opposing transverse end surfaces of the electrode active material layer, and a height HE that corresponds to the Feret diameter of the electrode active material layer as measured in the vertical direction between first and second opposing vertical end surfaces of the electrode active material layer, and a width WE that corresponds to the Feret diameter of the electrode active material layer as measured in the longitudinal direction between first and second opposing longitudinal end surfaces of the electrode active material layer, and each member of the population of counter-electrode structures comprises a layer of a counter-electrode active material having a length LC that corresponds to the Feret diameter of the counter-electrode active material layer as measured in the transverse direction between first and second opposing transverse end surfaces of the counter-electrode active material layer, and a height HC that corresponds to the Feret diameter of the counter-electrode active material layer as measured in the vertical direction between first and second opposing vertical end surfaces of the counter-electrode active material layer, and a width WC that corresponds to the Feret diameter of the counter-electrode active material layer as measured in the longitudinal direction between first and second opposing longitudinal end surfaces of the counter-electrode active material layer
• (iii) each unit cell comprises a unit cell portion of a first member of the electrode current collector of the electrode current collector population, a first electrode active material layer of one member of the electrode population, a member of the separator population that is ionically permeable to the carrier ions, a first counter-electrode active material layer of one member of the counter-electrode population, and a unit cell portion of a first member of the counter-electrode current collector of the counter-electrode current collector population, wherein (aa) the first electrode active material layer is proximate a first side of the separator and the first counter-electrode active material layer is proximate an opposing second side of the separator, and (bb) the separator electrically isolates the first electrode active material layer from the first counter-electrode active material layer, and carrier ions are primarily exchanged between the first electrode active material layer and the first counter-electrode active material layer via the separator of each such unit cell during cycling of the battery between the charged and discharged state, (cc) the first member of the electrode current collector population extends at least partially along the length LE of the electrode active material layer in the transverse direction and comprises an electrode current collector end that extends past the first transverse end surface of the counter-electrode active material layer of each such unit cell, and (dd) the first member of the counter-electrode current collector population extends at least partially along the length LC of the counter-electrode active material layer in the transverse direction and comprises a counter-electrode current collector end that extends past the second transverse end surface of the electrode active material layer in the transverse direction of each such unit cell,
• (iv) the number of electrode structures in the electrode structure population is at least 5, and the number of counter-electrode structures in the counter-electrode structure population is at least 5, and
• (c)(i) the electrode busbar comprises at least one conductive segment configured to electrically connect to the population of electrode current collectors, and extending in the longitudinal direction of the electrode assembly, the conductive segment of the electrode busbar being arranged with respect to the electrode current collector ends of members of the electrode current collector population such that the electrode current collector ends of members of the electrode current collector population are individually attached to the conductive segment via independent electrical connections, and
• (c)(ii) the counter-electrode busbar comprises at least one conductive segment configured to electrically connect to the population of counter-electrode current collectors, and extending in the longitudinal direction of the electrode assembly, the conductive segment of the counter-electrode busbar being arranged with respect to the counter-electrode current collector ends of members of the counter-electrode current collector population such that the counter-electrode current collector ends of members of the counter-electrode current collector population are individually attached to the conductive segment via independent electrical connections,
• (d) members of the population of first insulating layers and members of the population of second insulating layers are at respective first and second transverse end surfaces of counter-electrode active material layers of members of the counter-electrode structure population, the members of the populations of first and second insulating layers being disposed between the first and second transverse end surfaces of the counter-electrode active material layers and the respective electrode busbar and counter-electrode busbar proximate each of the first and second transverse end surfaces in the transverse direction,
• (e) the set of electrode constraints comprises a primary constraint system comprising first and second primary growth constraints and at least one primary connecting member, the first and second primary growth constraints separated from each other in the longitudinal direction, and the at least one primary connecting member connecting the first and second primary growth constraints, wherein the primary constraint system restrains growth of the electrode assembly in the longitudinal direction.