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JP-7857100-B2 - Battery cells and manufacturing processes including stretchable and compressible functional layers

JP7857100B2JP 7857100 B2JP7857100 B2JP 7857100B2JP-7857100-B2

Inventors

  • ツロドジェキ，マイケル
  • ウンニクリシュナン，サンディープ
  • ベルコーテレン，フランキー フローリー
  • ハベルカテ，ルーカス アウグスティヌス

Assignees

  • ネダーランゼ・オルガニサティ・フォーア・トゥーゲパスト－ナトゥールヴェテンシャッペリーク・オンデルゾエク・ティーエヌオー

Dates

Publication Date
20260512
Application Date
20191205
Priority Date
20181206

Claims (10)

  1. A rechargeable solid battery cell (1), - A first current collector (2) that is compressible and expandable, - A compressible and stretchable solid electrolyte (4), - A second current collector (6) that is compressible and expandable, The material includes a compressible and stretchable material (C) to form one or more functional layers, The compressible and stretchable material (C) comprises a plurality of compressible pores (P), and is configured to at least partially resist the compressive and/or tensile forces within the rechargeable solid battery cell resulting from volume changes of the negative and/or positive electrodes during charging and/or discharging of the cell. The compressible pores are provided by hollow latex beads (11) having a core-to-shell ratio (Vcore/Vshell) in the range of 5 to 0.05 in volume, and the hollow latex beads have a diameter in the range of 50 nanometers to 1 micrometer. A rechargeable solid battery cell (1) wherein the compressible pores have a diameter less than 20% of the thickness of the functional layer, which is made of the compressible and stretchable material (C) containing the pores.
  2. The rechargeable solid battery cell (1) according to claim 1, wherein the hollow latex beads have a diameter in the range of 200 to 1000 nanometers.
  3. The rechargeable solid battery cell (1) according to claim 1 or 2, wherein one or more of the first and second compressible and stretchable current collectors (2, 6) comprises the compressible and stretchable material (C) and an electronically conductive material to form the compressible and stretchable current collector.
  4. The rechargeable solid battery cell (1) according to claim 1 or 2, wherein the compressible and stretchable solid electrolyte (4) comprises the compressible and stretchable material (C) and the solid electrolyte material to form the compressible and stretchable solid electrolyte.
  5. The rechargeable solid battery cell (1) according to claim 3, wherein one or more of the first and second compressible and expandable current collectors are provided with conductive capping (8).
  6. The rechargeable solid battery cell (1) according to claim 3, wherein one or more of the first and second compressible and stretchable current collectors are at least partially provided with a conductive metal film to improve the uniform conductivity of the current collector along the interface with the electrode material.
  7. The stack of functional layers forms a substantially planar structure, or the cell is formed from a base current collector structure (16) including an array of conductive elements (17) spaced apart from each other and extending away from the base, and at least one of the electrodes and the solid electrolyte is provided between the elements, according to any one of claims 1 to 6, a rechargeable solid battery cell (1).
  8. A process for manufacturing a rechargeable solid battery cell (1) comprising a compressible and stretchable material (C), wherein the process is: - To provide a compressible and stretchable material (C) to form a compressible and stretchable first current collector (2), - To provide a compressible and stretchable material (C) to form a compressible and stretchable solid electrolyte (4), - Providing a compressible and stretchable material (C) to form a compressible and stretchable second current collector (6), and one or more of the above, By preparing a mixture comprising a stretchable continuous phase and one or more pore-forming agents, multiple compressible pores (P) are introduced into the compressible and stretchable material (C). By adding a solid electrolyte forming material, it becomes possible to form a compressible and expandable solid electrolyte, and by adding a current collector material, it becomes possible to form a compressible and expandable current collector. The compressible pores are provided by hollow latex beads (11) having a core-to-shell ratio (Vcore/Vshell) in the range of 5 to 0.05 in volume, and the hollow latex beads have a diameter in the range of 50 nanometers to 1 micrometer. The process wherein the compressible pores have a diameter of less than 20% of the thickness of the layer of the compressible and stretchable material (C).
  9. The process according to claim 8, wherein the stretchable continuous phase comprises a stretchable polymer.
  10. The hollow latex beads (11) are - Obtaining core-shell polymer latex beads in which the core contains an aqueous gel, - Drying the core-shell polymer latex beads by freeze-drying or by liquid-gas phase exchange treatment using a continuous dry gas flow, and optionally thereafter, The process according to claim 8 or 9, which is provided by applying a conductive coating (22) to the dried conductive hollow latex beads to form conductive hollow latex beads.

Description

Technical Field and Background This disclosure relates to solid-state batteries. In 3D and 2D all-solid-state batteries, the functional layers are typically bundled together compactly as a stack. In typical battery applications, the volume change between the discharged and charged states of a battery can be as much as 20%, for example, up to 1.2 times. Expansion within the stack, e.g., bulging, can be caused by the formation of a negative electrode, e.g., electrode layer, during the first charge cycle of a rechargeable battery. Correspondingly, during discharge, the volume of the negative electrode may decrease, e.g., shrink. In the case of microbatteries, where the amount of active material is very small and therefore the volume change during charging and discharging is very small, designs including densely integrated layers may work well. When moving to large-scale applications, e.g., 3D and 2D batteries with higher energy density, this may no longer be the case. Expansion of large volumes can lead to the formation of defects, e.g., the formation and/or propagation of cracks, and/or a decrease in interlayer ionic or electrical conductivity within the stack. Several different approaches exist that attempt to address the above problems to some extent. The first approach involves using a 3D-structured porous solid electrolyte on the current collector. Wang C.W. et al., Nano Lett. 17, 17, 565-571, describe a porous solid ceramic electrolyte compound in which, during charging, the lithium electrode material can fill existing pores in the solid electrolyte. However, this solution is only applicable to 2D batteries because the high sintering temperature required to produce the ceramics damages other components of the 3D structure. Furthermore, the large space occupied by the electrochemically inert ceramic material reduces the energy density of such batteries, e.g., energy per unit volume and energy-to-weight ratio. Additionally, the large surface contact area and long diffusion paths through the pores in the lithium plating are undesirable, as they can lead to parasitic reactions. The second method involves the formation of a porous current collector. Antunes M. et al., Polym. Sci. 2014, 39, 486-509, describes a lithium cell with a porous current collector formed from copper nanowires. During plating, lithium may fill the pores within the current collector. A disadvantage of using a porous conductive current collector is that, since it does not provide ionic conductivity, it can only be used in combination with a liquid electrolyte. If such a current collector is used in a lithium battery with a solid electrolyte, lithium will only plate at the interface between the current collector and the electrolyte, and will not fill the pores. A third method involves applying external pressure to the functional layer stack (e.g., a stretchable casing or spring at the pouch cell level). U.S. Patent No. 10786418 describes a pouch-type cell in a stretchable/plastic casing that maintains the stack under continuous pressure. This design reduces the loss of interlayer electrical contact during stack contraction. However, this design does not prevent volume expansion, which can still cause damage to the cell, such as cracking, and is therefore unsuitable for anode-free designs where large volume expansion is expected. Furthermore, plastic deformation of the cell stack is observed very frequently, leading to battery damage. A fourth approach involves providing a battery with a compressible and expandable inert layer. U.S. Patent Application Publication No. 20170365841 describes the encapsulation of an expandable layer within a cylindrical AAA-type zinc-air battery. In addition to introducing a large amount of electrochemically inert material, such a design cannot be used in lithium batteries because it adds an insulating layer between the functional layers to prevent charge transport across a continuous stack. Furthermore, such an approach results in a large amount of useless volume and mass (the inert portion of the battery), thus reducing the battery's energy density. This disclosure addresses one or more of the above limitations by describing a cell having a functional layer whose volume can be compressed and expanded in order to at least partially compensate for volume changes of other layers of the battery during charge-discharge cycles. This diagram shows schematic cross-sectional views of rechargeable battery cells in both the charged and discharged states, illustrating the volume change of the negative electrode between these states.This diagram shows a schematic cross-section of a rechargeable battery cell damaged due to crack formation.The diagram shows a schematic cross-section of a multi-layered stack, where a compressible and expandable composite material resists volume changes within the stack.This shows a schematic cross-sectional view of a rechargeable battery cell containing a compressible and expandable current