Electrode assembly and electrochemical cell including the same
An electrode assembly according to the present disclosure includes an electrode stack part formed by stacking at least one radical unit having a four-layered structure of a first electrode, a separator, a second electrode and a separator, and an electrode fixing part for wrapping and fixing the electrode stack part. The electrode assembly according to the present disclosure may be fabricated by means of a stacking process other than a folding process, and may accomplish accurate alignment and stable fixing.
1. An electrode assembly comprising: an electrode stack part obtained by stacking at least one radical unit including a four-layered structure of a first electrode, a first separator, a second electrode, and a second separator; and an electrode fixing part for wrapping and fixing the electrode stack part,
wherein the radical unit is formed by attaching the electrodes and the separators to each other,
wherein each of the electrodes includes an electrode current collector and an electrode active material coated on the electrode current collector,
wherein a first surface of the first separator is coated with a coating material having adhesiveness to allow the coating material of the first surface of the first separator to be adhered to the electrode active material of the first electrode,
wherein the coating material is a mixture of inorganic particles and a binder polymer, and
wherein a second surface of the first separator is uncoated with the coating material having adhesiveness to permit direct pressurization onto the second surface.
2. The electrode assembly of claim 1 , wherein the radical unit has an eight-layered structure obtained by repeatedly stacking the four-layered structures.
3. The electrode assembly of claim 2 , wherein the radical unit comprises a bicell formed by stacking the first electrode, the first separator, the second electrode, the second separator and the first electrode one by one, and a supplementary cell formed by stacking the first separator, the second electrode and the second separator one by one from one of the first electrode among the two of the first electrodes.
4. The electrode assembly of claim 2 , wherein the radical unit comprises a bicell formed by stacking the first electrode, the first separator, the second electrode, the second separator and the first electrode one by one, a first separator stacked on one of the first electrode among the two of the first electrodes, and a supplementary cell formed by stacking the second separator and the second electrode one by one from one of the other first electrode among the two of the first electrodes.
5. The electrode assembly of claim 1 , wherein the attachment of the first electrode and the first separator is an attachment through applying a pressure onto the first electrode and the first separator, or an attachment through applying a pressure and heat onto the first electrode and the first separator.
6. The electrode assembly of claim 1 , wherein the electrode fixing part comprises an upper fixing member provided on an upper portion of the electrode stack part, and a lower fixing member provided under the electrode stack part, the lower fixing member being connected with the upper fixing member, the lower fixing member and the upper fixing member closely fitting the electrode stack part.
7. The electrode assembly of claim 6 , wherein the lower fixing member is attached to the upper fixing member by means of an ultrasonic welding or a heat sealing.
8. The electrode assembly of claim 1 , wherein the electrode fixing part is obtained by wrapping the electrode stack part with a fixing sheet having a sheet shape.
9. The electrode assembly of claim 8 , wherein one end and the other end of the fixing sheet are attached to each other by means of an ultrasonic welding or a heat sealing to wrap the electrode stack part.
10. The electrode assembly of claim 1 , wherein the electrode fixing part has a tube shape providing a first opening, a second opening facing the first opening, and an inner space extended from the first opening to the second opening for receiving the electrode stack part.
11. The electrode assembly of claim 10 , wherein the electrode fixing part fits the electrode stack part by a contraction due to heat.
12. The electrode assembly of claim 1 , wherein the electrode fixing part is extended from an upper surface of the electrode stack part along a side surface of the electrode stack part to a lower surface of the electrode stack part to fix the electrode stack part.
13. The electrode assembly of claim 12 , wherein the electrode fixing part wraps the electrode stack part by at least one round.