KR102497815B1 - Watch strap having flexible battery - Google Patents

Abstract

A watch strap with a built-in flexible battery is provided. A watch strap with a built-in flexible battery according to an embodiment of the present invention includes a flexible battery including at least one electrode terminal having a predetermined length; and a soft housing covering the flexible battery to prevent the flexible battery from being exposed to the outside, wherein the flexible battery is embedded in the housing through insert molding, and the housing covers the electrode terminal. It includes a first part and a second part covering the remaining parts except for the electrode terminal, and the thickness of the first part at an arbitrary position is formed to have a relatively thicker thickness than the thickness of the second part at an arbitrary position. And, the flexible battery, the electrode assembly; an exterior material for sealing the electrode assembly together with an electrolyte solution; a first pattern formed on the exterior material such that peaks and valleys repeat along the longitudinal direction of the exterior material; and a second pattern formed on the electrode assembly to match the first pattern along the longitudinal direction of the electrode assembly, wherein the electrode assembly is disposed so that the second pattern matches the first pattern. It can be accommodated in the exterior material.

Description

Watch strap with flexible battery {Watch strap having flexible battery}

The present invention relates to a watch strap with a built-in flexible battery.

As consumer demand changes due to digitalization and high performance of electronic products, the market demand is also changing to the development of power supply devices with high capacity due to thin and light weight and high energy density.

Recently, the demand for mobile electronic devices such as mobile phones, laptop computers, and digital cameras is continuously increasing, and in particular, roll-type displays, flexible e-paper, and flexible liquid crystal displays (flexible-LCD) ), flexible organic light-emitting diode (OLED), etc. are applied, and interest in flexible mobile electronic devices is increasing. Accordingly, a power supply device for a flexible mobile electronic device is also required to have a flexible characteristic.

A flexible battery is being developed as one of the power supply devices that can reflect these characteristics.

As such a flexible battery, a pouch-type battery in which an electrode assembly including two electrodes and a separator is placed in a pouch together with an electrolyte and sealed is being developed.

Such a pouch-type battery has the advantage of being made of a material having flexibility, being able to be manufactured in various shapes, and being able to implement a high energy density per mass.

However, since the conventional pouch-type battery is implemented in a simple flexible form, if repeated bending occurs during use, the exterior material and electrode assembly are damaged due to repeated contraction and relaxation, or the performance is significantly reduced compared to the original design value, resulting in battery There are limits to its ability to function as a

As an example, when the flexible battery described above is applied to a watch strap fastened to a wearable device such as a smart watch, the watch strap is manufactured through injection molding after the flexible battery is embedded.

At this time, if the material of the watch band is made of a soft material such as silicon or leather to increase the user's wearing comfort, the watch band is repeatedly bent during the use process, so that the exterior material and the electrode assembly are repeatedly contracted and relaxed. There is a limitation in demonstrating the function as a battery because damage occurs or the performance is significantly reduced compared to the original design value.

On the other hand, in the flexible battery embedded in the watch strap, a pair of electrode terminals for electrical connection with the body of the smart watch protrude from the body by a certain length.

Since these electrode terminals serve as connection terminals for electrical connection with the body of the smart watch, they are typically made of a material such as copper foil or aluminum foil to increase electrical conductivity.

Accordingly, the electrode terminal may be easily cut by an impact applied from the outside due to weak rigidity due to the nature of the material itself.

For example, when the flexible battery is embedded in a soft housing to form a watch band, even if repeated bending occurs in the longitudinal direction, since the battery itself is made of a flexible material, it is possible to cope with this to some extent. However, if the watch band is twisted or an external force is applied to a part close to the position where the electrode terminal is embedded, the electrode terminal accommodated inside may be cut in the middle of the length.

Accordingly, even if the flexible battery is embedded in the watch band, since the electrode terminal is disconnected and power is not supplied to the wearable device, it cannot perform its function.

KR 10-2012-0023491 A

The present invention has been devised in view of the above points, and by forming a portion covering the electrode terminals to have a relatively thicker thickness than the rest, a watch strap with a built-in flexible battery capable of securing reliability against twisting or external force Its purpose is to provide

In addition, the present invention is formed so that the patterns formed respectively for contraction and relaxation in the longitudinal direction of the exterior material and the electrode assembly constituting the flexible battery coincide with each other, so that even if repeated bending occurs, deterioration of physical properties required as a battery is prevented or Another object is to provide a watch strap with a built-in flexible battery that can be minimized.

In order to solve the above problems, the present invention is a flexible battery including at least one electrode terminal having a predetermined length; and a soft housing covering the flexible battery to prevent the flexible battery from being exposed to the outside, wherein the flexible battery is embedded in the housing through insert molding, and the housing covers the electrode terminal. It includes a first part and a second part covering the remaining parts except for the electrode terminal, and the thickness of the first part at an arbitrary position is formed to have a relatively thicker thickness than the thickness of the second part at an arbitrary position. And, the flexible battery, the electrode assembly; an exterior material for sealing the electrode assembly together with an electrolyte solution; a first pattern formed on the exterior material such that peaks and valleys repeat along the longitudinal direction of the exterior material; and a second pattern formed on the electrode assembly to match the first pattern along the longitudinal direction of the electrode assembly, wherein the electrode assembly is disposed so that the second pattern matches the first pattern. A flexible battery accommodated in the exterior material provides a built-in watch band.

In addition, one end side of the electrode terminal may be directly exposed to one end of the first portion.

In addition, the first portion may include a connection terminal electrically connected to the electrode terminal, and the connection terminal may be embedded in the first portion such that at least a portion of the connection terminal is exposed to the outside. At this time, the connection terminal may be provided as a pin terminal.

In addition, the first portion may be provided to have the same cross-sectional area along the longitudinal direction, and the first portion may be formed such that the cross-sectional area decreases from the central portion toward both end portions in the width direction.

In addition, the housing may be made of a material having electrical insulation. For example, the housing may include at least one of a polyamide resin, a polyolefin resin, a polyethylene resin, and an epoxy resin.

In addition, the flexible battery may include a heat insulating layer for blocking heat transfer from the outside to the inside on at least a portion of an outer surface, and the heat insulating layer includes a porous substrate having a plurality of micropores capable of accommodating air, and One or more of the insulating films may be included.

Here, the porous substrate may include at least one substrate selected from the group consisting of a fibrous web, a nonwoven fabric, a woven fabric, and a knitted fabric, and the fibers forming the substrate may include at least one of organic fibers and inorganic fibers.

In addition, the fiber web is a nanofiber web formed through electrospinning, and the nanofibers forming the nanofiber web are polyacrylonitrile nanofibers, polyvinylidene fluoride nanofibers, and polyacrylonitrile and polyvinylidene fluoride nanofibers. It may include any one or more of the composite nanofibers of the ride.

delete

delete

In addition, the pattern may have ridges and valleys alternately formed along the longitudinal direction, and the ridges and valleys may have arc-shaped cross-sections, polygonal cross-sections, and cross-sections in which these cross-sections are combined.

In addition, the pattern may be formed entirely or partially along the longitudinal direction of the electrode assembly and the casing, and each peak and valley is continuously or discontinuously formed in a direction parallel to the width direction of the electrode assembly and the casing. It can be.

At this time, the intervals between the plurality of peaks or valleys adjacent to each other may be formed to have equal intervals or unequal intervals, or may be provided in the form of a mutual combination of equal intervals and unequal intervals, and the pattern may be formed continuously along the length direction or not. can be formed continuously.

In addition, the exterior material includes a first area for forming an accommodating portion accommodating the electrode assembly and the electrolyte, and a second area disposed to surround the first area to form a sealing portion, and is formed on the exterior material among the patterns. The pattern may be formed only in the first region.

In addition, the electrode assembly includes a positive electrode and a negative electrode configured by coating a part or all of an active material on a current collector, and a separator disposed between the positive electrode and the negative electrode, wherein the separator includes a porous nonwoven fabric layer having micropores, A nanofiber web layer containing polyacrylonitrile nanofibers may be included on one side or both sides of the nonwoven fabric layer. In this case, the active material may include PTFE to prevent cracking and separation from the current collector.

In addition, in the exterior material, a first resin layer, a metal layer, and a heat insulating layer may be sequentially stacked. The first resin layer is PPa (acid modified polypropylene), CPP (casting polyprolypene), LLDPE (Linear Low Density Polyethylene), LDPE (Low Density Polyethylene), HDPE (High Density Polyethylene), polyethylene terephthalate, polypropylene, ethylene vinyl It may be formed of a single layer of one selected from acetate (EVA), epoxy resin, and phenol resin, or may be configured by stacking two or more types. In addition, the metal layer is made of aluminum, copper, phosphorbronze (PB), aluminum bronze, cupronickel, beryllium-copper, chrome-copper, titanium-copper, iron-copper, Corson alloy and It may include one or more selected from chromium-zirconium copper alloys.

In addition, the exterior material further includes a second resin layer interposed between the metal layer and the heat insulating layer, and the second resin layer is made of nylon, polyethylene terephthalate (PET), cyclo olefin polymer (COP), polyimide (PI), and fluorine-based compounds. One or more selected species may be included.

In addition, a first adhesive layer interposed between the metal layer and the first resin layer is further included, and the first adhesive layer includes at least one selected from silicon, polyphthalate, PPa (acid modified polypropylene), and PEa (acid modified polyethylene). can do.

In addition, a dry lamination layer interposed between the metal layer and the second resin layer and a second adhesive layer interposed between the second resin layer and the heat insulating layer may be further included.

In addition, the electrolyte solution may include a gel polymer electrolyte solution.

According to the present invention, by configuring the portion covering the electrode terminal to have a relatively thicker thickness than the rest of the portion, it is possible to secure the reliability of the product by preventing the electrode terminal from being cut when twisting or external force occurs while securing flexibility.

In addition, the present invention is formed so that the patterns formed respectively for contraction and relaxation in the longitudinal direction of the exterior material and the electrode assembly constituting the flexible battery coincide with each other, so that even if repeated bending occurs, deterioration of physical properties required as a battery is prevented or can be minimized.

1 is a schematic diagram showing a watch strap with a built-in flexible battery according to an embodiment of the present invention;
2 is a view showing various longitudinal cross-sectional shapes of a first part applied to a watch strap with a built-in flexible battery according to the present invention;
3 and 4 are views showing various lateral cross-sectional shapes of a first part applied to a watch strap with a built-in flexible battery according to the present invention viewed from the direction AA of FIG. 1;
5 is a schematic diagram showing a watch strap with a built-in flexible battery according to another embodiment of the present invention;
6 is a schematic diagram showing a flexible battery applied to a watch strap with a built-in flexible battery according to the present invention;
7 is an enlarged view showing the detailed configuration of a flexible battery applied to a watch strap with a built-in flexible battery according to the present invention;
8 is a schematic diagram showing another type of flexible battery applied to a watch strap with a built-in flexible battery according to the present invention;
9 is an exemplary view showing various patterns applied to an electrode assembly and an exterior material in a flexible battery applied to a watch strap with a built-in flexible battery according to the present invention, showing various intervals between adjacent valleys or peaks;
10 is an exemplary diagram showing various patterns applied to an electrode assembly and an exterior material in a flexible battery applied to a watch strap with a built-in flexible battery according to the present invention, wherein the pattern is formed continuously or discontinuously over the entire length An example showing the case
11 to 14 are schematic views showing various cross-sectional shapes of patterns applied to a flexible battery applied to a watch band with a built-in flexible battery according to the present invention, and
15a and 15b are graphs showing the performance of a flexible battery applied to a watch strap with a built-in flexible battery according to the present invention, FIG. 15a is a graph showing the change in battery capacity before and after bending, and FIG. This is a graph showing the change in voltage of a battery over time when an external force is applied.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein. In order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are added to the same or similar components throughout the specification.

Watch straps 100 and 100' with a built-in flexible battery according to the present invention include a housing 110 and flexible batteries 120 and 120' as shown in FIGS. 1 and 5 .

The housing 110 is to protect the built-in flexible batteries 120 and 120' from the external environment, has a predetermined length, and is made of a soft material so that it can be wrapped around the user's body.

Here, the flexible batteries 120 and 120' are also provided to have flexibility, so that even when the housing 110 is wrapped around the user's body, performance as a battery can be exhibited.

At this time, the housing 110 is made of a material having electrical insulation to prevent electricity from flowing from the flexible batteries 120 and 120' to the user side when the built-in flexible batteries 120 and 120' operate.

For example, the housing 110 may include at least one of a polyamide resin, a polyolefin resin, a polyethylene resin, and an epoxy resin.

Accordingly, when the watch straps 100 and 100 ′ according to the present invention are applied to a wearable device such as a smart watch, the body of the wearable device can be worn on the user's body by being wound around the user's body.

In addition, even if the flexible batteries 120 and 120 ′ supply power to the main body of the wearable device while wearing the wearable device, it is possible to block the flow of electricity to the user.

The housing 110 has a first portion 111 covering the pair of electrode terminals 138 and 139 provided in the flexible batteries 120 and 120' and a second portion covering the rest except for the electrode terminals 138 and 139 ( 112).

That is, the first part 111 is for protecting a pair of electrode terminals 138 and 139 protruding a certain length from the exterior materials 121 and 122 of the flexible batteries 120 and 120', and the second part 112 is This is to protect the remaining parts of the flexible batteries 120 and 120' except for the pair of electrode terminals 138 and 139 protruding from the exterior materials 121 and 122.

Here, the pair of electrode terminals 138 and 139 are a positive terminal 139 and a negative terminal 138 respectively extending from the electrode assembly 130 accommodated in the exterior materials 121 and 122, and the flexible batteries 120 and 120' Power stored in the flexible batteries 120 and 120' can be supplied to the body of the wearable device by performing a role of electrically connecting an external device, for example, the body of the wearable device to each other.

As shown in FIG. 1, the pair of electrode terminals 138 and 139 may be directly exposed to the end side of the first portion 111, or as shown in FIG. 5, the pair of electrode terminals 138 and 139 Is electrically connected to a separate connection terminal 126, and at least a portion of the connection terminal 126 may be provided in a form exposed to the outside from the end side of the first portion 111.

Here, a known pin terminal may be used as the connection terminal 126 . Similar to the pair of electrode terminals 138 and 139, the connection terminal 126 may be embedded in the first part 111, but a part may protrude from the end of the first part 111.

However, it is not limited to this, and the entire connection terminal 126 is embedded in the first part 111, and a separate receiving groove is formed at the end side of the first part 111, and the inside of the receiving groove A portion of the connection terminal 126 may be provided in an exposed form.

In addition, it should be noted that the connection terminal may be provided in a form connected to the electrode terminals 138 and 139 by being made of a conductive material having a predetermined length and rigidity.

At this time, the thickness t1 of the first part 111 at an arbitrary position is provided to have a relatively thicker thickness than the thickness t2 of the second part 112 at an arbitrary position. This means that when the watch straps 100 and 100' composed of the flexible housing 110 and the flexible batteries 120 and 120' are twisted at a predetermined angle with respect to the longitudinal direction during use, the flexible batteries 120 and 120' are embedded. Even if the second part 112 is twisted, the first part 111 in which the electrode terminals 138 and 139 are embedded prevents twisting or minimizes twisting, so that the electrode terminals 138 and 139 built in the first part 111 This is to prevent breakage or breakage due to deformation due to twisting.

In addition, this is to protect the electrode terminals 138 and 139 from external force by absorbing the external force through a thick thickness even when an external force is generated on the side of the first portion 111 .

Through this, even if the pair of electrode terminals 138 and 139 are made of copper foil or aluminum foil, the length of the electrode terminals 138 and 139 is prevented or minimized and absorbs shock through a relatively thick thickness when twisting and external force occur. It is possible to prevent the middle from being cut off or the connection with the connection terminal 126 being cut off.

In addition, by making only the first part 111 in which the electrode terminals 138 and 139 are embedded have a relatively thick thickness with respect to the second part 112, even if the flexible batteries 120 and 120' are embedded, except for the first part 111 Since the remaining portion can have a thin thickness, the overall thickness can be reduced.

Here, the thickness of the second part 112 means the total thickness including the thickness of the flexible battery in the case where the flexible battery 120 or 120' is embedded, and the thickness of the first part 111 is In the case of the region S including the electrode terminals 138 and 139, it means the total thickness including the thickness of the electrode terminals 138 and 139.

The first part 111 may have various cross-sectional shapes. That is, as shown in FIG. 1, the first part 111 may have a rectangular cross-section, but as shown in (a) to (f) of FIG. 2, the first part 111 The longitudinal section may be provided to have various cross-sectional shapes.

For example, the first part 111 may be provided so that the longitudinal section decreases in thickness from the center to both ends (see FIGS. 2(a) to 2(c)), and the thickness is maintained constant. A portion and a portion having a reduced thickness may be provided in a combined form (see FIGS. 2(d) to 2(e)). Here, the portion where the thickness decreases may be provided as a curve (see FIG. 2 (a), FIG. 2 (b) and FIG. 2 (f)), or may be provided as a straight line (see FIG. 2 (c) ) to (e) reference), it may be provided in the form of a combination of curves and straight lines. In addition, the longitudinal section of the first part 111 may be provided so that the upper and lower parts are symmetrical to each other based on the center line (X) parallel to the width direction (Fig. 2 (a), Fig. 2 (c) to FIG. 2 (f)) may be provided asymmetrically (see FIG. 2 (b)), and the left and right parts may be provided symmetrically with respect to the center line (Y) parallel to the height direction, It may be provided asymmetrically.

However, the thickness t11 at an arbitrary position of the portion S including the area corresponding to the electrode terminals 138 and 139 among the longitudinal cross-sections of the first portion 111 is of the longitudinal cross-section of the second portion 112 It should be noted that any shape may be used as long as it has a relatively thicker thickness than the thickness t2 at an arbitrary position.

In addition, the first portion 111 may be provided to have the same cross-sectional area along the longitudinal direction or may be provided to have different cross-sectional areas (see FIGS. 3 and 4). In this case, the thickness t12 at any position of the first part 111 excluding the part connected to the second part 112 is the thickness at any position among the cross sections of the second part 112. It is clear that it is okay as long as it has a relatively thicker thickness than (t2).

The flexible batteries 120 and 120' are built into the housing 110 to supply power to the body of the wearable device when the watch straps 100 and 100' according to the present invention are fastened to a wearable device such as a smart watch.

Through this, it is possible to increase the use time of the wearable device.

Here, it should be noted that the flexible batteries 120 and 120' may be used as a driving power source for driving the wearable device, or may be used as an auxiliary battery to assist the main battery included in the wearable device.

At this time, the flexible batteries 120 and 120' are provided in a flexible form to enable bending together with the housing 110 made of a soft material.

As shown in FIG. 7, the flexible batteries 120 and 120' include an electrode assembly 130 and exterior materials 121 and 122, and the electrode assembly 130 is sealed inside the exterior materials 121 and 122 together with an electrolyte solution.

At this time, as shown in FIGS. 6 and 7 , the exterior materials 121 and 122 and the electrode assembly 130 are respectively provided with patterns 124 and 137 for contraction and relaxation in the longitudinal direction during bending, and the exterior materials 121 and 122 The first pattern 124 formed and the second pattern 137 formed on the electrode assembly 130 are provided to have the same direction.

Such patterns 124 and 137 offset the amount of change in length caused by a change in curvature at the bending portion of the flexible battery 120 and 120', thereby preventing or minimizing contraction or relaxation of the substrate itself.

Through this, since the amount of deformation of the base material itself constituting the exterior materials 121 and 122 and the electrode assembly 130 is prevented or minimized, even if repeated bending or bending occurs during use, the amount of deformation of the base material itself that can occur locally in the bent portion By being minimized, it is possible to prevent local damage or deterioration of performance of the exterior materials 121 and 122 and the electrode assembly 130 during bending.

At this time, the first pattern 124 and the second pattern 137 have the same orientation and are arranged so that the first pattern 124 and the second pattern 137 coincide with each other. This allows the first pattern 124 and the second pattern 137 to always have the same behavior, so that the first pattern 124 is always changed from the rolling state to the unfolded flat state or from the flat flat state to the rolling state. and the second pattern 137 to maintain the initial state.

This can be confirmed through the graphs of FIGS. 15A and 15B.

That is, when force is applied to both ends of the flexible battery in an environment of a temperature of 25° C. and a humidity of 105% to bend the flexible battery so that the curvature is 25 mm, and charging and discharging are performed 120 times, as shown in FIG. 15A In the case of the flexible battery (120, 120') according to the present invention, the capacity (110mAh) was reduced by approximately 15% compared to the capacity (130mAh) when it was not bent, and the performance was maintained even after 120 cycles (Example), but the exterior material In the case of a flexible battery in which a pattern for contraction and relaxation was formed only on the side, the performance gradually dropped at a capacity (52mAh) that was reduced by approximately 60% compared to the first one, and charging and discharging were impossible after 50 cycles (Comparative Example 1), exterior material In the case of the flexible battery provided in the form of a simple plate without a pattern formed in both the electrode assembly and the pattern, the capacity (26mAh) decreased by approximately 80% compared to the first time, and it was confirmed that charging and discharging were impossible if it exceeded 30 times. (Comparative Example 2).

On the other hand, as a result of measuring the voltage at the battery over time after returning to the original state from the fully folded state in the middle of the length of the flexible battery in an environment of a temperature of 25 ° C and a humidity of 105%, as shown in FIG. 15B, according to the present invention In the case of the flexible batteries 120 and 120', no change in voltage value occurred (Example), but the flexible battery formed a pattern for contraction and relaxation only on the exterior material side (Comparative Example 1), and both the exterior material and the electrode assembly had patterns It was confirmed that the voltage value of the flexible battery (Comparative Example 2) provided in the form of a simple plate that was not formed occurred.

In other words, when the patterns 124 and 137 for contraction and relaxation are formed to match each other on the exterior materials 121 and 122 and the electrode assembly 130, even if bending occurs, performance degradation does not occur significantly, while the pattern is formed only on the exterior material side Alternatively, it was confirmed that when the pattern is not formed on both the exterior material and the electrode assembly, cracks occur due to bending or leakage of the electrolyte solution occurs, resulting in deterioration in performance as a battery.

As such, the flexible batteries 120 and 120' applied to the present invention are formed so that the patterns 124 and 137 for contraction and relaxation in the longitudinal direction that occur when bending the exterior materials 121 and 122 and the electrode assembly 130 coincide with each other, Even if bending occurs due to rolling, the electrode assembly 130 and the exterior materials 121 and 122 can always maintain a uniform distance or contact state over the entire length, so that the electrolyte solution sealed with the electrode assembly 130 is It is possible to prevent performance as a battery from deteriorating by being uniformly distributed with respect to the battery.

To this end, each peak and valley of the first pattern 124 and the second pattern 137 is formed in a direction parallel to the width direction of the exterior materials 121 and 122 and the electrode assembly 130, and the exterior materials 121 and 122 ) and along the longitudinal direction of the electrode assembly 130, peaks and valleys are alternately disposed. In addition, the peaks and valleys constituting the first pattern 124 and the second pattern 137 are formed at the same position as the peaks and valleys, so that the first pattern 124 and the second pattern ( 137) to match each other.

Specifically, the ridges and valleys of the first pattern 124 and the second pattern 137 are formed in a direction parallel to a straight line parallel to the width direction of the exterior materials 121 and 122 and the electrode assembly 130, , the peaks and valleys are repeatedly arranged along the longitudinal direction (see FIG. 9).

At this time, the patterns 124 and 137 may be continuously formed in a direction parallel to the width direction of the electrode assembly 130 and the exterior materials 121 and 122 or may be formed discontinuously (Fig. 9 (a) to (d) ) reference), may be formed over the entire length of the electrode assembly 130 and the exterior materials 121 and 122 or partially formed over a partial length (see FIGS. 10(a) to (c)).

Here, the peaks and valleys may be provided to have any one of a cross section of an arc cross section including a semicircle, a polygon cross section including a triangle or a square, and a cross section of various shapes in which the arc cross section and the polygon cross section are mutually combined, and each The peaks and valleys may have the same pitch and width, but may have different pitches and widths (see FIGS. 11 to 14).

Through this, even if contraction and relaxation in the longitudinal direction of the exterior materials 121 and 122 and the electrode assembly 130 repeatedly occur due to repetitive bending, the changes in contraction and relaxation are offset through the patterns 124 and 137, thereby causing damage to the substrate itself. You can reduce fatigue.

On the other hand, the first pattern 124 and the second pattern 137 may be formed at the same interval between neighboring peaks or valleys as shown in (a) to (d) of FIG. It may be provided to have different intervals, or may be provided in a combination of the same interval and different intervals.

In addition, the first pattern 124 formed on the exterior materials 121 and 122 may be formed on the entire surface of the exterior materials 121 and 122 or may be partially formed.

For example, as shown in FIG. 8, in the flexible battery 120' according to the present invention, the first pattern 124 forms an accommodating portion for accommodating the electrode assembly 130 and the electrolyte solution in the first region S1 ) may be formed only.

This is because the electrolyte may move along the first pattern 124 by not forming the first pattern 124 on the side of the second area S2 constituting the sealing part in order to prevent leakage of the electrolyte to the outside. This is to block and improve the bonding force between the first exterior material 121 and the second exterior material 122 to increase confidentiality.

Here, when the first pattern 124 is formed only in the first region S1, the first pattern 124 may be formed over the entire area of the first region S1 or may be formed in a local area. And it should be noted that the electrode assembly 130 may be formed only in an area corresponding to an area corresponding to that of the electrode assembly 130 .

The exterior materials 121 and 122 are made of plate-shaped members having a certain area, and are intended to protect the electrode assembly 130 from external force by accommodating the electrode assembly 130 and the electrolyte therein.

To this end, the exterior materials 121 and 122 are provided with a pair of first and second exterior materials 121 and 122, and are sealed along the edges with an adhesive so that the electrolyte and electrode assembly 130 accommodated inside are removed from the outside. to prevent exposure and leakage to the outside.

That is, the first exterior material 121 and the second exterior material 122 are arranged to surround the first area S1 forming an accommodation part for accommodating the electrode assembly and the electrolyte solution, and the electrolyte solution and a second region S2 forming a sealing portion to block the leakage to the outside.

In the case of the exterior materials 121 and 122, after the first and second exterior materials 121 and 122 are composed of two members, the edge side constituting the sealing part may be both sealed with an adhesive or made of one member. After being folded in half along the width direction or length direction, the rest of the butted portion may be sealed through an adhesive.

The exterior materials 121 and 122 may be provided in a form in which metal layers 121b and 122b are interposed between the first resin layers 121a and 122a and the second resin layers 121c and 122c. That is, the exterior materials 121 and 122 are configured in the form of sequentially stacking first resin layers 121a and 122a, metal layers 121b and 122b, and second resin layers 121c and 122c, and the first resin layer ( 121a and 122a are disposed inside to contact the electrolyte, and the second resin layers 121c and 122c are exposed to the outside (see FIG. 7).

At this time, the first resin layers 121a and 122a are PPa (acid modified polypropylene), CPP (casting polypropylene), LLDPE (Linear Low Density Polyethylene), LDPE (Low Density Polyethylene), HDPE (High Density Polyethylene), polyethylene tere It may include a single layer structure of one of phthalate, polypropylene, ethylene vinyl acetate (EVA), epoxy resin and phenol resin, or a laminated structure thereof, preferably PPa (acid modified polypropylene), CPP (casting polyprolypene), It may be composed of a single layer selected from LLDPE (Linear Low Density Polyethylene), LDPE (Low Density Polyethylene), and HDPE (High Density Polyethylene), and may be composed of two or more of these being laminated.

Also, the first resin layers 121a and 122a may have an average thickness of 20 μm to 100 μm.

When the average thickness of the first resin layers 121a and 122a is less than 20 μm, the first resin layer 121a abuts each other in the process of sealing the edge sides of the first and second exterior materials 121 and 122. , 122a) may be disadvantageous in securing airtightness to prevent leakage of the electrolyte or decrease in bonding strength between them, and if the average thickness exceeds 100 μm, it is uneconomical and disadvantageous to thinning. However, it should be noted that the thickness of the first resin layer is not limited thereto and may be variously changed according to design conditions.

The metal layers 121b and 122b are interposed between the first resin layers 121a and 122a and the second resin layers 121c and 122c to prevent moisture from penetrating from the outside toward the receiving part and allow the electrolyte to flow from the receiving part to the outside. This is to prevent leakage.

To this end, the metal layers 121b and 122b may be formed of metal layers having a high density so that moisture and electrolyte cannot pass therethrough. The metal layers 121b and 122b are formed on a foil-type metal sheet or on the second resin layers 121c and 122c to be described later by a conventionally known method, such as sputtering or chemical vapor deposition. It may be formed of a metal deposited film, preferably a thin metal plate, through which cracks in the metal layer are prevented during pattern formation to prevent leakage of the electrolyte solution to the outside or permeation of moisture from the outside.

For example, the metal layers 121b and 122b may include aluminum, copper, phosphorbronze (PB), aluminum bronze, cupronickel, beryllium-copper, chrome-copper, titanium-copper, iron- It may include at least one selected from copper, Corson alloy, and chromium-zirconium copper alloy.

In this case, the metal layers 121b and 122b may have linear expansion coefficients of 1.0 to 1.7×10 ^-7 /°C, preferably 1.2 to 1.5×10 ^-7 /°C. If the coefficient of linear expansion is less than 1.0 × 10 ^-7 / ° C, sufficient flexibility cannot be secured, and cracks may occur due to external force generated during bending, and the coefficient of linear expansion exceeds 1.7 × 10 ^-7 / ° C. This is because rigidity is lowered and severe deformation of the shape may occur.

The metal layers 121b and 122b may have an average thickness of 5 μm or more, preferably 5 μm to 120 μm, and more preferably 30 μm to 50 μm.

This is because when the average thickness of the metal layer is less than 5 μm, moisture may permeate into the containing part or the electrolyte inside the containing part may leak to the outside. However, it should be noted that the thickness of the metal layer is not limited thereto and may be variously changed according to design conditions.

The second resin layers 121c and 122c are located on the exposed surfaces of the exterior materials 121 and 122 to reinforce the strength of the exterior materials and to prevent damage such as scratches to the exterior materials due to physical contact applied from the outside. will be.

The second resin layers 121c and 122c may include one or more selected from among nylon, polyethylene terephthalate (PET), cyclo olefin polymer (COP), polyimide (PI), and fluorine-based compounds, preferably nylon or A fluorine-based compound may be included.

Here, the fluorine-based compound is selected from polytetra fluoroethylene (PTFE), perfluorinated acid (PFA), fluorinated ethelene propylene copolymer (FEP), polyethylene tetrafluoro ethylene (ETFE), polyvinylidene fluoride (PVDF), ethylene chlorotrifluoroethylene (ECTFE), and polychlorotrifluoroethylene (PCTFE). One or more selected species may be included.

In this case, the second resin layers 121c and 122c may have an average thickness of 8 μm to 50 μm, preferably an average thickness of 15 μm to 40 μm, and more preferably 15 μm to 35 μm. can

This is because if the average thickness of the second resin layers 121c and 122c is less than 8 μm, mechanical properties cannot be secured, and if it exceeds 50 μm, it is advantageous to secure mechanical properties, but is uneconomical and disadvantageous to thinning. However, it should be noted that the thickness of the second resin layer is not limited thereto and may be variously changed according to design conditions.

Meanwhile, the flexible batteries 120 and 120' according to the present invention may further include an adhesive layer between the metal layers 121b and 122b and the first resin layers 121a and 122a.

The adhesive layer serves to increase the adhesive strength between the metal layers 121b and 122b and the first resin layers 121a and 122a, and prevents the electrolyte solution contained inside the packaging material from reaching the metal layers 121b and 122b of the packaging material. Corrosion of the metal layers 121b and 122b or separation between the first resin layers 121a and 122a and the metal layers 121b and 122b can be prevented by the acidic electrolyte.

In addition, even when the flexible battery swells due to a problem such as abnormal overheating during use of the flexible battery 120 or 120', leakage of the electrolyte may be prevented, thereby providing reliability in safety.

The adhesive layer may be made of a material similar to that of the first resin layers 121a and 122a. For example, the adhesive layer may include at least one selected from silicone, polyphthalate, acid modified polypropylene (PPa), and acid modified polyethylene (Pea).

Such an adhesive layer serves to increase the adhesive strength between the metal layers 121b and 122b and the second resin layers 121c and 122c, and safety even if problems such as abnormal overheating occur during the use of the flexible batteries 120 and 120'. and reliability against internal short circuits.

In this case, the adhesive layer may have an average thickness of 5 μm to 30 μm, preferably 10 μm to 20 μm. If the average thickness of the adhesive layer exceeds 5 μm, it may be difficult to secure stable adhesion, and if it exceeds 30 μm, it is disadvantageous to thinning.

Meanwhile, the flexible batteries 120 and 120' according to the present invention may further include a dry lamination layer between the metal layers 121b and 122b and the second resin layers 121c and 122c.

The dry laminate layer plays a role of bonding the metal layers 121b and 122b and the second resin layers 121c and 122c, and may be formed by drying a known water- and/or oil-based organic solvent type adhesive.

In this case, the dry laminate layer may have an average thickness of 1 μm to 7 μm, preferably 2 μm to 5 μm, and more preferably 2.5 μm to 3.5 μm.

This means that if the average thickness of the dry laminate layer is less than 1 μm, peeling may occur between the metal layers 121b and 122b and the second resin layers 121c and 122c because the adhesive force is too weak, and if it exceeds 7 μm, dry laminate is unnecessary. This is because the thickness of the layer may adversely affect the formation of patterns for contraction and relaxation.

On the other hand, the electrode assembly 130 is sealed together with the electrolyte inside the exterior materials 121 and 122, and includes an anode 132, a cathode 136, and a separator 134 as shown in FIG.

The positive electrode 132 includes a positive electrode current collector 132a and a positive electrode active material 132b, and the negative electrode 136 includes a negative electrode current collector 136a and a negative electrode active material 136b, and the positive electrode current collector 132a ) and the negative electrode current collector 136a may be implemented in the form of a plate-shaped sheet having a predetermined area.

That is, the active materials 132b and 136b may be compressed, deposited, or coated on one side or both sides of the respective current collectors 132a and 136a of the positive electrode 132 and the negative electrode 136 . In this case, the active materials 132b and 136b may be provided on the entire area of the current collectors 132a and 136a or may be partially provided on a partial area of the current collectors 132a and 136a.

Here, the negative electrode current collector 136a and the positive electrode current collector 132a may be made of a thin metal foil and may be made of copper, aluminum, stainless steel, nickel, titanium, chromium, manganese, iron, cobalt, zinc, molybdenum, tungsten, It may be made of silver, gold, or a mixture thereof.

In addition, the cathode current collector 132a and the cathode current collector 136a have a negative terminal 138 and a positive terminal 139 for electrical connection with external devices formed from respective bodies. Here, the positive terminal 139 and the negative terminal 138 extend from the positive current collector 132a and the negative current collector 136a and protrude from one side of the exterior materials 121 and 122 .

Meanwhile, the cathode active material 132b includes a cathode active material capable of reversibly intercalating and deintercalating lithium ions, and representative examples of such a cathode active material include LiCoO ₂ , LiNiO ₂ , LiNiCoO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , V ₂ O ₅ , V ₆ O ₁₃ , LiNi _{1 -x- y} Co _x M _y O ₂ (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ x+y ≤ 1, where M is A lithium-transition metal oxide such as a metal such as Al, Sr, Mg, or La, or a lithium nickel cobalt manganese (NCM)-based active material may be used, and a mixture of one or more of them may be used.

In addition, the anode active material 136b includes an anode active material capable of reversibly intercalating and deintercalating lithium ions, and the anode active material includes crystalline or amorphous carbon, carbon fiber, or carbon of a carbon composite. It may be selected from the group consisting of a negative electrode active material, tin oxide, a lithiated product thereof, lithium, a lithium alloy, and a mixture of one or more of them. Here, carbon may be at least one selected from the group consisting of carbon nanotubes, carbon nanowires, carbon nanofibers, graphite, activated carbon, graphene, and graphite.

However, the cathode active material and the anode active material used in the present invention are not limited thereto, and it should be noted that both the cathode active material and the anode active material commonly used may be used.

In this case, in the present invention, a polytetrafluoroethylene (PTFE) component may be contained in the positive active material 132b and the negative active material 136b. This is to prevent the cathode active material 132b and the anode active material 136b from being peeled off or cracked from the current collectors 132a and 136a during bending.

Such a PTFE component may be 0.5 to 20 wt%, preferably 5 wt% or less, based on the total weight of each of the cathode active material 132b and the anode active material 136b.

Meanwhile, the separator 134 disposed between the anode 132 and the cathode 136 may include a nanofiber web layer 134b on one or both sides of the nonwoven fabric layer 134a.

Here, the nanofiber web layer 134b may be nanofibers containing at least one selected from polyacrylonitrile nanofibers and polyvinylidene fluoride nanofibers.

Preferably, the nanofiber web layer 134b may be composed of only polyacrylonitrile nanofibers to secure spinnability and uniform pore formation. Here, the polyacrylonitrile nanofibers may have an average diameter of 0.1 to 2 μm, preferably 0.1 to 1.0 μm.

This means that if the average diameter of the polyacrylonitrile nanofibers is less than 0.1 μm, there may be a problem in that the separator does not secure sufficient heat resistance, and if it exceeds 2 μm, the mechanical strength of the separator is excellent, but the elasticity of the separator may rather decrease. because it can

In addition, when a gel polymer electrolyte solution is used as the separator 134, a composite porous separator may be used to optimize the impregnation of the gel polymer electrolyte solution.

That is, the composite porous separator may include a porous nonwoven fabric having micropores used as a support (matrix), and a porous nanofiber web formed of a spinnable polymer material and impregnated with an electrolyte solution.

Here, the porous non-woven fabric is composed of a PP non-woven fabric, a PE non-woven fabric, a non-woven fabric made of PP / PE fibers of a dual structure coated with PE on the outer circumference of the PP fiber as a core, and a three-layer structure of PP / PE / PP, and has a relatively melting point. Any one of a nonwoven fabric having a shutdown function due to this low PE, a PET nonwoven fabric made of polyethyleneterephthalate (PET) fibers, or a nonwoven fabric made of cellulose fibers can be used. The PE nonwoven fabric may have a melting point of 120 to 120°C, the PP nonwoven fabric may have a melting point of 130 to 150°C, and the PET nonwoven fabric may have a melting point of 230 to 250°C.

At this time, the porous nonwoven fabric preferably has a thickness of 10 to 40 μm, a porosity of 5 to 55%, and a Gurley value of 1 to 1200 sec/120c.

On the other hand, the porous nanofibrous web may use either a swellable polymer that swells in an electrolyte solution alone or a mixed polymer in which a heat-resistant polymer capable of enhancing heat resistance is mixed with the swellable polymer.

Such a porous nanofiber web is formed by dissolving a single or mixed polymer in a solvent to form a spinning solution, and then spinning the spinning solution using an electrospinning device, and the spun nanofibers are accumulated in the collector to have a three-dimensional pore structure. A porous nanofiber web is formed.

Here, the porous nanofiber web can be used as long as it is dissolved in a solvent to form a spinning solution and then spun by an electrospinning method to form nanofibers. For example, the polymer may be a single polymer or a mixed polymer, and a swellable polymer, a non-swellable polymer, a heat-resistant polymer, a mixed polymer of a swellable polymer and a non-swellable polymer, a mixed polymer of a swellable polymer and a heat-resistant polymer may be used. can

At this time, when the porous nanofiber web uses a mixed polymer of a swellable polymer and a non-swellable polymer (or a heat-resistant polymer), the weight ratio of the swellable polymer and the non-swellable polymer is in the range of 9:1 to 1:9, preferably 8: They can be mixed in a weight ratio ranging from 2 to 5:5.

In general, in the case of non-swellable polymers, many of them are generally heat-resistant polymers and have a relatively high melting point because they have a high molecular weight compared to swellable polymers. Accordingly, the non-swellable polymer is preferably a heat-resistant polymer having a melting point of 180° C. or higher, and the swellable polymer is preferably a resin having a melting point of 150° C. or less, preferably within a range of 120 to 150° C.

On the other hand, the swellable polymer that can be used in the present invention is a resin that swells in an electrolyte solution and can be formed into ultrafine nanofibers by electrospinning.

For example, the swellable polymer is polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene), perfluoropolymer, polyvinyl chloride or polyvinylidene chloride and copolymers thereof, and Polyethylene glycol derivatives including polyethylene glycol dialkyl ethers and polyethylene glycol dialkyl esters, poly(oxymethylene-oligo-oxyethylene), polyoxides including polyethylene oxide and polypropylene oxide, polyvinyl acetate, poly(vinyl group) Rolidone-vinyl acetate), polystyrene and polystyrene acrylonitrile copolymers, polyacrylonitrile copolymers including polyacrylonitrile methyl methacrylate copolymers, polymethyl methacrylate, polymethyl methacrylate copolymers, and A mixture of one or more of these may be used.

In addition, the heat-resistant polymer or non-swellable polymer can be dissolved in an organic solvent for electrospinning, swelling occurs more slowly than the swellable polymer or does not swell by the organic solvent included in the organic electrolyte, and the melting point is 180 ° C. or higher. can be used

For example, the heat-resistant polymer or non-swellable polymer is polyacrylonitrile (PAN), polyamide, polyimide, polyamideimide, poly(meta-phenylene isophthalamide), polysulfone, polyetherketone, polyethylenetere Aromatic polyesters such as phthalate, polytrimethylenetelephthalate, polyethylene naphthalate, etc., polytetrafluoroethylene, polydiphenoxyphosphazene, poly{bis[2-(2-methoxyethoxy)phosphazene]} Polyurethane copolymers including phosphazenes, polyurethane and polyether urethane, cellulose acetate, cellulose acetate butylate, cellulose acetate propionate, and the like can be used.

On the other hand, the nonwoven fabric constituting the nonwoven fabric layer 134a is cellulose, cellulose acetate, polyvinyl alcohol (PVA, polyvinyl alcohol), polysulfone, polyimide, polyetherimide, polyamide ( polyamide), polyethylene oxide (PEO), polyethylene (PE, polyethylene), polypropylene (PP, polypropylene), polyethylene terephthalate (PET), polyurethane (PU), polymethyl methacrylate (PMMA, poly methylmethacrylate) and polyacrylonitrile (polyacrylonitrile) can be used.

Here, the nonwoven fabric layer may further include an inorganic additive, and the inorganic additive is SiO, SnO, SnO ₂ , PbO ₂ , ZnO, P ₂ O ₅ , CuO, MoO, V ₂ O ₅ , B ₂ O ₃ , Si ₃ N ₄ , CeO ₂ , Mn ₃ O ₄ , Sn ₂ P ₂ O ₇ , Sn ₂ B ₂ O ₅ , Sn ₂ BPO ₆ , TiO ₂ , BaTiO ₃ , Li ₂ O, LiF, LiOH, Li ₃ N, At least one selected from BaO, Na ₂ O, Li ₂ CO ₃ , CaCO ₃ , LiAlO ₂ , SiO ₂ , Al ₂ O ₃ and PTFE may be included.

In addition, the inorganic particles as the inorganic additive may have an average particle diameter of 10 to 50 nm, preferably 10 to 30 nm, and more preferably 10 to 20 nm.

In addition, the average thickness of the separator may be 10 ~ 120㎛, preferably 10 ~ 50㎛. This is because if the average thickness of the separator is less than 10㎛, the separator is too thin, so it may not be possible to secure long-term durability of the separator due to repeated bending and / or unfolding of the battery, and if it exceeds 120㎛, it is disadvantageous to thinning the flexible battery. It is preferable to have an average thickness within the above range.

In addition, the nonwoven fabric layer has an average thickness of 10 to 30 μm, preferably 15 to 30 μm, and the nanofiber web layer preferably has an average thickness of 1 to 5 μm.

On the other hand, as the electrolyte solution sealed in the accommodating part together with the electrode assembly 130, a commonly used liquid electrolyte solution may be used.

For example, the electrolyte solution may use an organic electrolyte solution containing a non-aqueous organic solvent and a solute of lithium salt. Here, carbonate, ester, ether or ketone may be used as the non-aqueous organic solvent. Examples of the carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC), and ethylene carbonate (EC) , Propylene carbonate (PC), butylene carbonate (BC), etc. may be used, and the ester includes butyrolactone (BL), decanolide, valerolactone, mevalonolactone ), caprolactone, n-methyl acetate, n-ethyl acetate, n-propyl acetate, etc. may be used, and dibutyl ether may be used as the ether, and polymethylvinyl ketone may be used as the ketone. However, the present invention is not limited to the type of non-aqueous organic solvent.

In addition, the electrolyte used in the present invention may include a lithium salt, and the lithium salt serves as a source of lithium ions in the battery to enable basic operation of the lithium battery, examples of which include LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF 6 , LiClO ₄ , LiCF ₃ SO ₃ , LiN(CF ₃ SO ₂ ) ₂ , LiN ₍ C ₂ F ₅ SO ₂ ) ₂ , LiAlO ₄ , LiAlCl ₄ , LiN(C _x F _{2x + 1} SO ₂ ) (C _y F _{2x + 1} SO ₂ ) (where x and y are rational numbers) and LiSO ₃ CF ₃ may include one or more selected from the group consisting of or a mixture thereof.

At this time, although a liquid electrolyte may be used as the electrolyte used in the flexible batteries 120 and 120' according to the present invention, a gel polymer electrolyte may be preferably used. Through this, the flexible batteries 120 and 120' according to the present invention use a polymer electrolyte in a gel state as the electrolyte, thereby preventing leaks and leaks that may occur during bending when liquid is used as the electrolyte of the flexible battery. .

The gel polymer electrolyte may be formed by gelation heat treatment of an organic electrolyte solution containing a non-aqueous organic solvent, a solute of lithium salt, a monomer for forming a gel polymer, and a polymerization initiator.

In such a gel polymer electrolyte, the organic electrolyte may be heat treated alone, but the separator provided inside the flexible battery is heat treated while impregnated with the organic electrolyte to in-situ polymerize the monomer to form a gel polymer in a gel state. (134) can be implemented in a form impregnated with pores. The in-situ polymerization reaction in the flexible battery proceeds through thermal polymerization, and the polymerization time takes about 20 minutes to 12 hours, and the thermal polymerization may be performed at 40 to 90 °C.

At this time, as the monomer for forming the gel polymer, any monomer may be used as long as the polymer forms the gel polymer while the polymerization reaction is performed by the polymerization initiator. For example, methyl methacrylate (MMA), polyethylene oxide (PEO), polypropylene oxide (PPO), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polymethacrylate (PMA), Monomers for polymethyl methacrylate (PMMA) or its polymers, and polyacrylates having two or more functional groups such as polyethylene glycol dimethacrylate and polyethylene glycol acrylate can be exemplified.

In addition, examples of the polymerization initiator include benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tertbutylperoxide, cumyl hydroperoxide ( Organic peroxides or hydroperoxides such as cumyl hydroperoxide) and hydrogen peroxide, 2,2-Azobis(2-cyanobutane), 2, and azo compounds such as 2-azobis (methylbutyronitrile) (2,2-Azobis (methylbutyronitrile)). The polymerization initiator is decomposed by heat to form radicals, and reacts with monomers through free radical polymerization to form a gel polymer electrolyte, that is, a gel polymer.

The monomer for forming the gel polymer is preferably used in an amount of 1 to 10% by weight based on the organic electrolyte solution. If the content of the monomer is less than 1, it is difficult to form a gel-type electrolyte, and if it exceeds 10% by weight, there is a problem of life degradation. In addition, the polymerization initiator may be included in an amount of 0.01 to 5% by weight based on the monomer for forming the gel polymer.

Meanwhile, in the flexible batteries 120 and 120′ applied to the present invention, as shown in FIG. 7 , insulating layers 121d and 122d may be provided on surfaces of the exterior materials 121 and 122 constituting the flexible batteries 120 and 120′. At this time, the heat insulating layers 121d and 122d may be formed on the entire surface of the exterior materials 121 and 122 or partially.

When the flexible battery 120 is embedded in the housing 110 through insert molding, the heat insulating layers 121d and 122d block the movement of high heat applied during insert molding to the flexible battery 120, thereby reducing the function of the battery. However, it performs a function to prevent the occurrence of defects.

Meanwhile, in the flexible batteries 120 and 120' embedded in the watch strap according to the present invention, patterns for contraction and relaxation in the longitudinal direction are formed on the exterior materials 121 and 122 and the electrode assembly 130, respectively, so that the exterior materials 121 and 122 Curves due to the pattern exist on the surface.

Accordingly, in order to most effectively contract and relax the flexible battery in the longitudinal direction during the bending process, the inner surface of the housing 110 covering the flexible batteries 120 and 120' is integrally bonded to the outer surface of the battery. desirable.

That is, in order to match the surfaces of the exterior materials 121 and 122 curved by the pattern with the inner surface of the housing 110 contacting each other, it is preferable to construct the housing through insert molding.

If the upper housing and the lower housing of the housing 110 are separately formed through a mold, a flexible battery is placed between the upper housing and the lower housing, and then combined using an adhesive, etc., high heat required during insert molding Since the process is omitted, the problem of occurrence of defects or degradation of the flexible battery due to heat may not fundamentally occur.

However, if the same pattern as the pattern formed on the exterior materials 121 and 122 is not separately formed on the inner surfaces of the upper housing and the lower housing in contact with the surface of the flexible battery, specifically the exterior materials 121 and 122, the pattern formed on the flexible battery As a result, a gap inevitably occurs between the surfaces of the exterior materials 121 and 122 and the inner surface of each housing.

This gap does not fix the flexible battery accommodated inside the housing, so there is a problem in that the battery moves inside the housing. In addition, when bending, a problem of crinkling or wrinkles may occur in a part where a gap occurs, which may degrade performance as a battery.

In addition, even if patterns are formed on the mold to have the same pattern as the pattern formed on the outer surface of the flexible battery, arranging them to match each other during the molding process is very difficult, and there is a problem in that the manufacturing cost may significantly increase.

However, in the flexible battery applied to the present invention, by disposing a heat insulating layer on the surface of an exterior material, even if a process of applying high temperature heat during insert molding is performed, the heat insulating layer can prevent functional degradation or defects of the flexible battery due to heat. Perfect contact and attachment to the inner surface of the housing can be achieved even if there is a pattern-based curve on the surface of the exterior material.

In addition, the heat insulating layers 121d and 122d block the transfer of heat generated from the flexible battery itself to the outside through the housing when the flexible battery 120 or 120' operates, thereby preventing the user from feeling uncomfortable or anxious due to heat. there is.

Such heat insulating layers 121d and 122d may be implemented as thin films, and may be used without limitation in the case of known heat insulating members having heat resistance capable of maintaining their shape at high temperatures, for example, 150 ° C. or higher, preferably 180 ° C. or higher. there is.

For example, the heat insulating layers 121d and 122d may include a porous substrate having a plurality of micropores capable of accommodating air and/or a heat insulating film.

The porous substrate may include at least one substrate selected from the group consisting of a fiber web, a nonwoven fabric, a woven fabric, and a knitted fabric. The woven and knitted fabrics refer to conventional fabrics in which fibers are arranged in a direction and/or regularity.

In addition, the fiber web and nonwoven fabric refer to substrates formed by gathering fibers without orientation, and the fiber web forms a three-dimensional network structure by fusion between fibers without a separate bonding process or adhesive at the same time as spinning. It means a base material, and the non-woven fabric refers to a conventional non-woven fabric manufactured by attaching short fibers to each other through a separate adhesive or heat. Fibers forming the porous substrate as described above are cellulose-based, protein, polyester-based (PET, PBT, etc.), polyamide-based (nylon 6, nylon 66, etc.), acrylic-based (polyacrylonitrile, modacrylic, etc.), olefin Known organic fibers including (polypropylene, polyethylene, etc.), vinyl (polyvinyl alcohol, polyvinyl chloride, etc.) and fluorine (PVDF, PCTFE, PTFE, etc.) and/or inorganic fibers such as glass fibers and rock wool fibers can be fibres.

In addition, the heat insulation layers 121d and 122d may be fibrous webs, for example nanofiber webs formed through electrospinning. The nanofibers forming the nanofiber web may include polyacrylonitrile nanofibers to have heat resistance capable of withstanding high heat.

In addition, the nanofibers themselves forming the nanofiber web may include polyvinylidene fluoride nanofibers to improve durability and mechanical strength by expressing adhesiveness.

Here, the nanofibers may be composite nanofibers of polyacrylonitrile and polyvinylidene fluoride. This is to enable the simultaneous expression of durability and mechanical strength through heat resistance and adhesiveness.

In this case, the composite nanofibers may be composite nanofibers in which polyacrylonitrile and polyvinylidene fluoride are mixed in a weight ratio of 6:4 to 8.5:1.5 in mono yarns. This is because when PAN and PVDF are included in a ratio of less than 6:4, the heat resistance is lowered and the melting of the nanofiber web occurs while the insulation effect is expressed, so that the pores of the nanofiber web are significantly reduced and the insulation effect is not properly expressed. Because there may be problems.

In addition, when PAN and PVDF are included in a ratio exceeding 8.5:1.5, it is difficult to develop mechanical strength and durability, and due to the high ratio of PAN, spinnability may be significantly reduced during electrospinning, which may lead to poor productivity, and porosity of a desired level It is difficult to manufacture a nanofiber web that exhibits sufficient insulation effect because it is difficult to implement the tile and hole diameter. Furthermore, this is because there may be a problem in that the adhesion between the external housing and the flexible battery manufactured by the nanofiber web and insert molding may be reduced.

In addition, the average diameter of the nanofibers forming the nanofiber web may be 0.1 μm to 2 μm, preferably 0.1 μm to 1.0 μm. This means that if the average diameter of the nanofibers is less than 0.1 μm, sufficient porosity may not be secured, resulting in poor thermal insulation, and if it exceeds 2 μm, the pores formed by the nanofibers are too large, resulting in poor thermal insulation. because it can

On the other hand, the nanofibrous web has a basis weight of 2 to 6 g/m2, a porosity of 40% or more, more preferably 40 to 80%, and an average pore diameter of 300 to 400 μm. . This is because, when the porosity of the nanofibrous web exceeds 80% and/or the average pore diameter exceeds 400 μm, the mechanical strength of the nanofibrous web is weak and may not properly function as a heat insulating layer.

Such heat insulating layers 121d and 122d may be implemented as a structure in which a plurality of heat insulating layers are stacked. For example, a nanofibrous web layer and a nonwoven fabric layer may be laminated, and the thickness of the nanofibrous web may be 3 to 10 μm, and the thickness of the nonwoven fabric may be 10 to 40 μm.

Here, the nonwoven fabric itself serves as a heat insulating layer and at the same time supplements the mechanical strength of the laminated nanofiber web to further improve the durability of the heat insulating layer.

On the other hand, in the drawings and description, it has been shown and described that the heat insulation layers 121d and 122d are provided on the surfaces of the exterior materials 121 and 122, but it is not limited thereto, and the positive terminal protrudes from the electrode assembly 130 to the outside of the exterior material ( 139) and the negative electrode terminal 138 may also have the heat insulation layers 121d and 122d provided.

In this way, the watch straps 100 and 100 ′ with a built-in flexible battery according to the present invention form a pattern for contraction and relaxation in the longitudinal direction in the flexible battery 120 itself, so that the pattern is formed even if repeated bending in the longitudinal direction occurs. Maintaining performance as a battery through and thickening the thickness of the first part 111 in which the electrode terminals 138 and 139 are accommodated to prevent the electrode terminals 138 and 139 from being damaged by twisting or external force, enabling stable operation Product reliability can be increased.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention may add elements within the scope of the same spirit. However, other embodiments can be easily proposed by means of changes, deletions, additions, etc., but these will also fall within the scope of the present invention.

100,100' : Watch strap with built-in flexible battery
110: housing 111: first part
112: second part 120,120': flexible battery
121: first exterior material 122: second exterior material
121a, 122a: first resin layer 121b, 122b: metal layer
121c, 122c: second resin layer 121d, 121d: insulation layer
124: pattern 126: connection terminal
130: electrode assembly 132: anode
132a: cathode current collector 132b: cathode active material
134: separator 134a: non-woven fabric layer
134b: nanofiber web layer 136: cathode
136a: anode current collector 136b: anode active material
137: pattern 138: negative terminal
139: positive terminal

Claims (21)

A flexible battery including at least one electrode terminal having a predetermined length; and
A soft housing covering the flexible battery to prevent the flexible battery from being exposed to the outside; includes,
The flexible battery is embedded in the housing through insert molding,
The housing includes a first part covering the electrode terminal and a second part covering the rest except for the electrode terminal,
The thickness at any position of the first part is formed to have a relatively thicker thickness than the thickness at any position of the second part,
The flexible battery,
electrode assembly;
an exterior material for sealing the electrode assembly together with an electrolyte solution;
a first pattern formed on the exterior material such that peaks and valleys are repeated along the longitudinal direction of the exterior material; and
A second pattern formed on the electrode assembly to coincide with the first pattern along the longitudinal direction of the electrode assembly; including,
The electrode assembly is a flexible battery-embedded watch strap accommodated in the exterior material so that the second pattern is aligned with the first pattern. According to claim 1,
The first portion includes a connection terminal electrically connected to the electrode terminal,
A watch band with a built-in flexible battery provided in the first portion such that at least a portion of the connection terminal is exposed to the outside. According to claim 1,
The first portion is a watch strap with a built-in flexible battery, the thickness of which decreases from the central portion of the width toward both end portions in the width direction. According to claim 1,
A watch band with a built-in flexible battery, wherein the flexible battery has an insulating layer provided on at least a portion of an outer surface thereof to block heat from moving from the outside to the inside. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

Images