TWI643393B - Battery structure - Google Patents

Abstract

The invention discloses a battery structure, which mainly comprises a first collector layer, a second collector layer smaller than the first collector layer in the forward projection direction, a first collector layer and a second collector layer. a plastic frame between the layers to form a surrounding area, the sealing area is provided with an electrochemical system layer, and an insulating layer is disposed on at least one of the first collecting layer and the second collecting layer, by a first and a second collector layer of a non-equal length design in the forward projection direction, and an insulating layer disposed on at least one of the first collector layer and the second collector layer to avoid the first current after bending The layer and the second collector layer cause an external short circuit due to contact.

Description

Battery structure

The invention relates to a battery structure, in particular to a battery structure, which has the effect of avoiding external short circuits.

Under the demand of human technology, various wearable electronic devices have been created accordingly. In order to make various wearable electronic devices more suitable for thin and light, space allocation in electronic devices has become an important issue, and can be set in a non-planar flexible type. The battery brings one of the solutions to this problem. Please refer to FIG. 1 , which is a cross-sectional view showing the structure of a current flexible solid state lithium battery. As shown, the battery structure 40 mainly includes a first collector layer 42, a second collector layer 44, and a plastic frame 46 sandwiched between the first collector layer 42 and the second collector layer 44. Forming a surrounding area, the contents of the enclosed area are sequentially provided with a first active material layer 50, a separating layer 52 and a second active material layer 54, a first active material layer 50, a separating layer 52 and a second active material. The material layer 54 constitutes the electrochemical system layer 56, and the first active material layer 50 is in contact with the first collector layer 42, and the second active material layer 54 is in contact with the second collector layer 44. The flexible solid-state lithium battery is characterized in that it is dynamically bendable as a whole, but an external short circuit occurs due to the contact of the first collector layer 42 with the second collector layer 44 during the bending process.

In view of the above, the present invention has been directed to the absence of the above-described prior art, and proposes a battery structure to effectively overcome the above problems.

The object of the present invention is to provide a battery structure in which the upper collector layer and the lower collector layer are different in length, and the periphery of at least one of the first collector layer or the second collector layer is electrically Insulation to avoid the external short circuit caused by the contact of the first and second collector layers when the battery is bent.

In order to achieve the above object, the present invention provides a battery structure, The battery mainly includes a first collector layer, a second collector layer smaller than the first collector layer in the forward projection direction, and a plastic frame sandwiched between the first collector layer and the second collector layer, and At least part of the plastic frame overlaps with the first collector layer and the second collector layer in the direction of the projection, so that the plastic frame, the first collector layer and the second collector layer together form a surrounding area, and the content of the enclosure area An electrochemical system layer comprising a first active material layer, a second active material layer and an isolation layer disposed between the first active material layer and the second active material layer, the first active material layer and the first set Contacting the electrical layer, the second active material layer is in contact with the second collector layer, and an insulating layer is disposed on at least one of the first collector layer and the second collector layer to avoid the first collector layer after the bending The second collector layer generates an external short circuit due to contact.

In order to achieve the above object, the present invention provides another battery structure. The battery mainly includes a first collector layer, a second collector layer smaller than the first collector layer in the front projection direction, and a second collector layer. a plastic frame between the collector layer and the second collector layer, and at least a portion of the plastic frame overlaps the first collector layer and the second collector layer in the forward projection direction, so that the plastic frame, the first collector layer, and the first layer The two collector layers together form a surrounding area, the sealing area is provided with an electrochemical system layer, comprising a first active material layer, a second active material layer and a first active material layer and a second An isolation layer between the active material layers, the first active material layer is in contact with the first collector layer, and the second active material layer is in contact with the second collector layer, at least one of the first collector layer and the second collector layer The edge has an insulating layer, and at least a portion of the insulating layer is covered by the plastic frame to avoid an external short circuit caused by the contact between the first collector layer and the second collector layer after the bending.

In order to achieve the above object, the present invention provides a battery structure. The battery mainly includes a first collector layer, a second collector layer smaller than the first collector layer in the front projection direction, and a second collector layer. a plastic frame between the collector layer and the second collector layer, and at least a portion of the plastic frame overlaps the first collector layer and the second collector layer in the forward projection direction, so that the plastic frame, the first collector layer, and the first layer The two collector layers together form a surrounding area, the sealing area is provided with an electrochemical system layer, comprising a first active material layer, a second active material layer and a first active material layer and a second An isolation layer between the active material layers, the first active material layer is in contact with the first collector layer, and the second active material layer is in contact with the second collector layer, at least in the first collector layer and the second collector layer One of the peripheral edges has an insulating layer, and the insulating layer covers at least part of the plastic frame to avoid an external short circuit caused by the contact between the first collector layer and the second collector layer after the bending.

The purpose, technical content, features and effects achieved by the present invention will be more readily understood by the detailed description of the embodiments.

10, 40‧‧‧ battery structure

12, 42‧‧‧ first collector layer

14, 44‧‧‧Second collector layer

16, 46‧‧‧ plastic frame

161‧‧‧First colloid layer

162‧‧‧Second colloid layer

163‧‧‧ third colloid layer

20, 50‧‧‧ first active material layer

22, 52‧‧‧ isolation layer

24, 54‧‧‧Second active material layer

26, 56‧‧ ‧ electrochemical system layer

28‧‧‧Insulation

30‧‧‧Protective layer

T‧‧‧ Height

D‧‧‧ size difference

Figure 1 is a cross-sectional view showing the structure of a currently flexible solid state lithium battery.

2A to 2D are schematic views showing the structure of the first embodiment of the present invention.

3A to 3C are schematic views showing the structure of the second embodiment of the present invention.

4A to 40 are schematic views showing the structure of the second embodiment of the present invention.

5A-1 to 5A-9 are schematic views showing the structure of the second embodiment of the present invention.

5B-1 to 5B-27 are schematic views showing the structure of the second embodiment of the present invention.

5C-1 to 5C-27 are schematic views showing the structure of the second embodiment of the present invention.

6A to 6I are schematic views showing the structure of the third embodiment of the present invention.

The invention provides a solution to the problem that the flexible solid lithium battery is externally short-circuited due to mutual contact between the first and second collector layers after bending.

Please refer to FIG. 2A, which is a schematic structural view of a first embodiment of the present invention. As shown in the figure, the battery structure 10 mainly includes a first collector layer 12, a second collector layer 14 that is smaller than the first collector layer 12 in the front projection direction, and a first collector layer. a plastic frame 16 between the 12 and the second collector layer 14 , wherein the plastic frame 16 is at least partially overlapped with the first collector layer 12 and the second collector layer 14 in the forward projection direction, and is firstly collected by the first collector. The layer 12, the second collector layer 14 and the plastic frame 16 together form a surrounding area, the sealing area is provided with an electrochemical system layer 26, and the electrochemical system layer 26 comprises a first active material layer 20, a first The second active material layer 24 and the isolation layer 22 disposed between the first active material layer 20 and the second active material layer 24, the first active material layer 20 is in contact with the first collector layer 12, and the second active material layer 24 is The second collector layer 14 is in contact, An insulating layer 28 is disposed on at least one of the periphery of the first collector layer 12 and the second collector layer 14 by the difference in length between the first collector layer 12 and the second collector layer 14 in the orthogonal projection direction, and The insulating layer is disposed to prevent the first collector layer 12 and the second collector layer 14 from contacting each other when bent to generate an external short circuit. The periphery defined herein is a surface comprising a side surface and/or extending upward and/or downward from the side surface. The insulating layer 28 is a separate structure and/or a part of the plastic frame 16, and/or a structure that is electrically insulated by surface treatment.

In addition, as shown in FIG. 2B, the plastic frame 16 of the battery structure includes a first colloid layer 161 and a second colloid layer 162, and the first colloid layer 161 is adhered to the first collector layer 12, and the second colloid layer is bonded. 162 is bonded to the second collector layer 14. Furthermore, as shown in FIG. 2C, the plastic frame 16 of the battery structure may further include a first colloid layer 161, a second colloid layer 162 and a third colloid layer 163, and the third colloid layer 163 is sandwiched between Between the first colloid layer 161 and the second colloid layer 162.

Please refer to FIG. 3A, 3B, and 3C, which are schematic diagrams of the first structure of the second embodiment of the present invention. As shown in the figure, the battery structure mainly includes a first collector layer 12, a second collector layer 14 that is smaller than the first collector layer 12 in the front projection direction, and a first collector layer 12 a plastic frame 16 between the second collector layer 14 and the second collector layer 14 at least partially overlapped with the first collector layer 12 and the second collector layer 14 in the forward projection direction, by using the first collector layer 12, the second collector layer 14 and the plastic frame 16 together form a surrounding area, the enclosure area is provided with an electrochemical system layer 26, the electrochemical system layer 26 comprises a first active material layer 20, a second The active material layer 24 and the isolation layer 22 disposed between the first active material layer 20 and the second active material layer 24, the first active material layer 20 is in contact with the first collector layer 12, and the second active material layer 24 is The second collector layer 14 is in contact with an insulating layer 28 at least one of the periphery of the first collector layer 12 and the second collector layer 14, and at least a portion of the insulating layer 28 is covered by the bezel 16 by the first episode The difference in length between the electrical layer 12 and the second collector layer 14 in the orthogonal projection direction, and the arrangement of the insulating layer to avoid the first collector layer 12 and the second episode Generating an external short circuit at the contact layer 14 is bent. The periphery defined herein is a surface comprising a side surface and/or extending upward and/or downward from the side surface. Wherein the insulating layer 28 is a separate structure and/or is part of the bezel 16 and/or is electrically insulated by surface treatment. Constructor.

In addition, the plastic frame 16 of the battery structure may include a first colloid layer 161 and a second colloid layer 162. The first colloid layer 161 is bonded to the first collector layer 12, and the second colloid layer 162 and the second collector layer are electrically collected. The layer 14 is bonded, and at least one of the first colloid layer 161 and the second colloid layer 162 is coated with at least a portion of the insulating layer 28, that is, at least partially as shown in FIGS. 4D, 4E, and 4F. The insulating layer 28 is covered by the first colloid layer 161, or as shown in Figures 4A, 4B and 4C, at least part of the insulating layer 28 is covered by the second colloid layer 162, or as shown in Figures 4G to 4O. As shown, at least a portion of the insulating layer 28 is covered by the first colloid layer 161 and the second colloid layer 162.

Furthermore, the plastic frame 16 of the battery structure may further include a first colloid layer 161, a second colloid layer 162 and a third colloid layer 163. The third colloid layer 163 is interposed between the first colloid layer 161 and the second colloid layer. Between 162, at least one of the first colloid layer 161, the second colloid layer 162, and the third colloid layer 163 is coated with at least a portion of the insulating layer 28. That is, in the case where the insulating layer 28 is covered only by one of the first colloid layer 161, the second colloid layer 162, and the third colloid layer 163, it may be as in 5A-1, 5A-2, and 5A. As shown in FIG. 3, at least a portion of the insulating layer 28 is covered by the second colloid layer 162, or as shown in FIGS. 5A-4, 5A-5, and 5A-6, at least a portion of the insulating layer 28 is covered by the third colloid layer. 163 coating, or as shown in Figures 5A-7, 5A-8, and 5A-9, at least a portion of the insulating layer 28 is covered by the first colloid layer 161; at the same time, the insulating layer 28 is simultaneously coated by the first colloid layer 161, In the case where two of the second colloid layer 162 and the third colloid layer 163 are coated, at least a portion of the insulating layer 28 may be the second colloid layer 162 as shown in FIGS. 5B-1 to 5B-9. And coating the third colloid layer 163, or as shown in FIGS. 5B-10 to 5B-18, at least a portion of the insulating layer 28 is covered by the first colloid layer 161 and the third colloid layer 163, or 5B-19 to 5B-27, at least a portion of the insulating layer 28 is covered by the first colloid layer 161 and the second colloid layer 162; the insulating layer 28 is covered by the first colloid layer 161 and the second colloid layer 162. And the third colloid layer 163 is simultaneously wrapped In other words, as shown in FIGS. 5C-1 to 5C-27, the insulating layer 28 may be changed depending on the first colloid layer 161, the second colloid layer 162, and the third colloid layer 163.

Please refer to the drawings of FIGS. 6A, 6B and 6C, which are schematic diagrams of the third embodiment of the present invention. As shown in the figure, the battery structure mainly includes one The first collector layer 12 is smaller than the second collector layer 14 of the first collector layer 12 and the plastic frame 16 sandwiched between the first collector layer 12 and the second collector layer 14 in the forward projection direction. The plastic frame 16 is at least partially overlapped with the first collector layer 12 and the second collector layer 14 in the forward projection direction, and is configured to pass through the first collector layer 12, the second collector layer 14, and the bezel 16 Forming a surrounding area, the enclosed area is provided with an electrochemical system layer 26, the electrochemical system layer 26 includes a first active material layer 20, a second active material layer 24 and a first active material. The isolation layer 22 between the layer 20 and the second active material layer 24, the first active material layer 20 is in contact with the first collector layer 12, and the second active material layer 24 is in contact with the second collector layer 14, in the first collector An insulating layer 28 is formed on at least one of the periphery of the layer 12 and the second collector layer 14, and the insulating layer 28 is coated with at least a portion of the plastic frame 16 by the first collector layer 12 and the second collector layer 14 being positive. The difference in length in the projection direction and the arrangement of the insulating layer prevent the first collector layer 12 and the second collector layer 14 from coming into contact with each other when bent to cause an external short circuit. The periphery defined herein is a surface comprising a side surface and/or extending upward and/or downward from the side surface. The insulating layer 28 is a separate structure and/or a part of the plastic frame 16, and/or a structure that is electrically insulated by surface treatment.

In addition, please refer to the figures 6D, 6E and 6F. As shown in the figure, the plastic frame 16 of the battery structure may include a first colloid layer 161 and a second colloid layer 162, and the first colloid layer 161 and the first collector layer. The layer 12 is bonded, and the second colloid layer 162 is bonded to the second collector layer 14. In addition, please refer to the figures 6G, 6H and 6I. As shown in the figure, the plastic frame 16 of the battery structure may further comprise a first colloid layer 161, a second colloid layer 162 and a third colloid layer 163, and a third The colloid layer 163 is interposed between the first colloid layer 161 and the second colloid layer 162.

Furthermore, in all of the above embodiments, the battery structure 10 may further include a protective layer 30. Referring again to FIG. 2A, the protective layer 30 is disposed on at least one of the first collector layer 12 and the second collector layer 14. An outer surface is exemplified by the first collector layer 12, and the protective layer 30 is disposed on the other surface of the first active material layer 20, wherein the protective layer 30 is a separate structure and/or as shown in FIG. 2D. The protective layer 30 is a part of the insulating layer 28.

Moreover, in the structure of all the above embodiments, the covering condition between the insulating layer and the plastic frame can be changed according to requirements, for example, in the battery structure. When the insulating layer of the first embodiment is covered by the periphery of the first collector layer and at least part of the insulating layer of the second embodiment is covered by the frame, there are of course three embodiments in the same battery structure. The situation. In the case where the protective layer is present in the present invention, the structure of the collector layer can be protected, and the metal surface of the collector layer can be prevented from being oxidized or broken by impact.

According to the battery structure of the present invention, since the upper end surface of the plastic frame is adhered to the first collector layer, the lower end surface of the plastic frame is adhered to the second collector layer, so that the electrochemical system layer completely accommodated in the enclosed area is The positive projection direction will appear completely in the region of the first collector layer and/or the second collector layer, that is, the orthographic projection area of the first active material layer is smaller than the orthographic projection area of the first collector layer, The orthographic projection area of the two active material layers is smaller than the orthographic projection area of the second collector layer.

In addition, in the orthographic projection direction, the plastic frame may be completely or partially located in the orthographic projection area of the first collector layer and the second collector layer, that is, when the plastic frame is completely located in the first collector. When the first collector layer and the second collector layer have the same length in the cross section of the second collector layer, the mask frame does not protrude from the first collector layer and the first layer. In addition to the two collector layers, if the first collector layer and the second collector layer have different lengths in cross section, the glue frame is located in the orthographic projection area where the first collector layer and the second collector layer intersect. If the plastic frame is locally located in the front projection area of the first collector layer and the second collector layer, it means that whether the first collector layer and the second collector layer have the same length in the cross section or not, The partial plastic frames all appear to protrude beyond the first collector layer and the second collector layer.

Referring to FIG. 2A, the difference between the size of the first collector layer and the second collector layer in the forward projection direction is D, and the height of the frame is T, and D is not greater than T. The reason why D must not be larger than T is that since the bent D has the thickness of the collector layer itself, in the case of D=T, even if the bending is 90 degrees, it does not contact the other collector layer.

In a general lithium battery, after the active material layer is coated on the collector layer and then subjected to a cutting and drying process to form a so-called positive electrode or a negative electrode, the active material layer of the positive electrode or the negative electrode is the same size as the collector layer, based on safety factors. Under the consideration, the positive active material layer must be smaller than the design of the negative active material layer, that is, the positive electrode must It must be smaller than the negative electrode. The so-called safety factor is because if lithium ions are inserted into the negative electrode, if the space of the negative electrode is insufficient, lithium dendrite is formed in a large amount, which causes the lithium dendrite to puncture the isolation layer and cause short-circuiting of the internal positive and negative electrode contacts. In the lithium battery architecture of the present case, the size of the collector layer is not related to the size of the positive and negative electrodes described above. In other words, the smaller collector layer previously described in the present case may also be the collector layer of the negative electrode, and a larger collector. The layer may also be a collector layer of the positive electrode. The collector layer of the present invention has a size difference in order to avoid a short circuit problem of contact of the external collector layer. For this reason, please refer to FIG. 2A. In this figure, the first collector layer 12 may be a positive collector layer or a cathode collector layer, and the second collector layer 14 is corresponding to a cathode collector layer or a cathode assembly. Electrical layer. That is to say, when the first collector layer 12 is a negative collector layer, the second collector layer 14 is a cathode collector layer, which is different from the existing general lithium battery architecture.

In summary, the present invention provides insulation by using first and second collector layers of non-equal length in the forward projection direction and at least one of the periphery of the first collector layer and the second collector layer. The layer can prevent the first and second collector layers from being contacted after the bending of the flexible solid lithium battery, thereby avoiding the external short circuit caused by the contact of the first and second collector layers.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Therefore, any changes or modifications of the features and spirits of the present invention should be included in the scope of the present invention.

Claims (38)

A battery structure includes: a first collector layer; a second collector layer that is smaller than the first collector layer in a right projection direction; and a plastic frame that is sandwiched between the first collector Between the layer and the second collector layer, and at least partially overlapping the first collector layer and the second collector layer in a front projection direction, the plastic frame, the first collector layer and the second collector layer Forming a surrounding area; an electrochemical system layer disposed in the enclosed area, the electrochemical system layer comprising a first active material layer, a second active material layer and a first active material layer disposed thereon And a barrier layer between the second active material layer, the first active material is in contact with the first collector layer, the second active material layer is in contact with the second collector layer; and an insulating layer is disposed on the layer a periphery of at least one of the first collector layer and the second collector layer; wherein the periphery comprises a side surface and/or a surface extending upward and/or downward from the side surface. The battery structure of claim 1, wherein the plastic frame covers at least a portion of the insulating layer. The battery structure of claim 1, wherein the plastic frame comprises a first colloid layer and a second colloid layer, the first colloid layer is adhered to the first collector layer, and the second colloid layer and the first colloid layer The two collector layers are bonded. The battery structure of claim 3, wherein at least a portion of the insulating layer is covered by at least one of the first colloid layer and the second colloid layer. The battery structure of claim 3, wherein the plastic frame further comprises a third colloid layer interposed between the first colloid layer and the second colloid layer. The battery structure of claim 5, wherein at least a portion of the insulating layer is covered by at least one of the first colloid layer, the second colloid layer, and the third colloid layer. The battery structure of claim 1, wherein the electrochemical system layer is located within the second collector layer in a right projection direction. The battery structure of claim 7, wherein the first active material layer has an orthographic projection area that is smaller than an orthographic projection area of the first collector layer. The battery structure of claim 7, wherein the second active material layer has an orthographic projection area that is smaller than an orthographic projection area of the second collector layer. The battery structure of claim 1, wherein the difference between the size of the first collector layer and the second collector layer in the forward projection direction is D, and the height of the frame is T, then D is not greater than T . The battery structure according to claim 1, wherein the insulating layer is a separate structure and/or is a part of the plastic frame and/or a structure that is electrically insulated by surface treatment. The battery structure of claim 1, further comprising a protective layer disposed on at least one of the first collector layer and the second collector layer. The battery structure of claim 12, wherein the protective layer is a separate structure and/or is part of the insulating layer. The battery structure of claim 1, which is a flexible battery. A battery structure includes: a first collector layer; a second collector layer that is smaller than the first collector layer in a right projection direction; and a plastic frame that is sandwiched between the first collector Between the layer and the second collector layer, and at least partially overlapping the first collector layer and the second collector layer in a front projection direction, the plastic frame, the first collector layer and the second collector layer Forming a surrounding area; an electrochemical system layer disposed in the enclosed area, the electrochemical system layer comprising a first active material layer, a second active material layer and a first active material layer disposed thereon And a barrier layer between the second active material layer, the first active material is in contact with the first collector layer, the second active material layer is in contact with the second collector layer; and an insulating layer is disposed on the layer At least one of the first collector layer and the second collector layer, and at least a portion of the insulating layer is covered by the frame; wherein the periphery comprises a side surface and/or upward from the side surface / or the surface extending below. The battery structure of claim 15, wherein the plastic frame comprises a first colloid layer and a second colloid layer, the first colloid layer is adhered to the first collector layer, and the second colloid layer and the first colloid layer The two collector layers are bonded. The battery structure of claim 16, wherein at least a portion of the insulating layer is covered by at least one of the first colloid layer and the second colloid layer. The battery structure of claim 16, wherein the plastic frame further comprises a third colloid layer interposed between the first colloid layer and the second colloid layer. The battery structure of claim 18, wherein at least a portion of the insulating layer is covered by at least one of the first colloid layer, the second colloid layer, and the third colloid layer. The battery structure of claim 15, wherein the electrochemical system layer is located within the second collector layer in a right projection direction. The battery structure of claim 20, wherein the first active material layer has an orthographic projection area that is smaller than an orthographic projection area of the first collector layer. The battery structure of claim 20, wherein the second active material layer has an orthographic projection area that is smaller than an orthographic projection area of the second collector layer. The battery structure of claim 15, wherein the difference between the size of the first collector layer and the second collector layer in the forward projection direction is D, and the height of the frame is T, then D is not greater than T . The battery structure of claim 15 wherein the insulating layer is a separate structure and/or is part of the frame and/or is structurally electrically insulated by surface treatment. The battery structure of claim 15, further comprising a protective layer disposed on at least one of the first collector layer and the second collector layer. The battery structure of claim 25, wherein the protective layer is a separate structure and/or is part of the insulating layer. The battery structure of claim 15 which is a flexible battery. A battery structure comprising: a first collector layer; a second collector layer, which is smaller than the first collector layer in the forward projection direction; a plastic frame sandwiched between the first collector layer and the second collector layer, and in the orthographic projection direction At least partially overlapping the first collector layer and the second collector layer, the glue frame, the first collector layer and the second collector layer form a surrounding area; an electrochemical system layer Provided in the enclosed area, the electrochemical system layer comprises a first active material layer, a second active material layer and an isolation layer disposed between the first active material layer and the second active material layer, the first An active material is in contact with the first collector layer, the second active material layer is in contact with the second collector layer; and an insulating layer is disposed on the first collector layer and the second collector layer One of the circumferences and covering at least a portion of the frame; wherein the periphery comprises a side surface and/or a surface extending upward and/or downward from the side surface. The battery structure of claim 28, wherein the plastic frame comprises a first colloid layer and a second colloid layer, the first colloid layer is adhered to the first collector layer, and the second colloid layer and the first colloid layer The two collector layers are bonded. The battery structure of claim 29, wherein the plastic frame further comprises a third colloid layer interposed between the first colloid layer and the second colloid layer. The battery structure of claim 28, wherein the electrochemical system layer is located within the second collector layer in a right projection direction. The battery structure of claim 31, wherein the first active material layer has an orthographic projection area that is smaller than an orthographic projection area of the first collector layer. The battery structure of claim 31, wherein the second active material layer has an orthographic projection area that is smaller than an orthographic projection area of the second collector layer. The battery structure of claim 28, wherein the difference between the size of the first collector layer and the second collector layer in the forward projection direction is D, and the height of the frame is T, then D is not greater than T . The battery structure of claim 28, wherein the insulating layer is a separate structure and/or is part of the frame and/or is structurally electrically insulated by surface treatment. The battery structure of claim 28, further comprising a protective layer disposed on at least one of the first collector layer and the second collector layer. The battery structure of claim 36, wherein the protective layer is a separate structure and/or is part of the insulating layer. The battery structure of claim 28, which is a flexible battery.