U.S. patent application number 14/995005 was filed with the patent office on 2017-01-19 for electrochromic device and process for making the same.
The applicant listed for this patent is Tintable Kibing Co., Ltd.. Invention is credited to Yi-Wen Chung, Cheng-Hao Liu.
Application Number | 20170017132 14/995005 |
Document ID | / |
Family ID | 57682216 |
Filed Date | 2017-01-19 |
United States Patent
Application |
20170017132 |
Kind Code |
A1 |
Liu; Cheng-Hao ; et
al. |
January 19, 2017 |
ELECTROCHROMIC DEVICE AND PROCESS FOR MAKING THE SAME
Abstract
An electrochromic device includes upper and lower substrate
units, and an electrochromic laminate sandwiched between an upper
electrode of the upper substrate unit and a lower electrode of the
lower substrate unit. The electrochromic laminate includes an ion
storage layer formed on the upper electrode, an active layer formed
on the lower electrode, and a polymer electrolyte sandwiched
between inner surfaces of the ion storage layer and the active
layer. At least one of the inner surfaces has a roughened
peripheral region such that an adhesion force generated between the
roughened peripheral region and the polymer electrolyte is
effective to minimize thermal shrinkage of the polymer
electrolyte.
Inventors: |
Liu; Cheng-Hao; (Tainan
City, TW) ; Chung; Yi-Wen; (Tainan City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Tintable Kibing Co., Ltd. |
Tainan City |
|
TW |
|
|
Family ID: |
57682216 |
Appl. No.: |
14/995005 |
Filed: |
January 13, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F 1/153 20130101;
G02F 2001/164 20190101; G02F 1/1524 20190101 |
International
Class: |
G02F 1/153 20060101
G02F001/153; B29C 65/14 20060101 B29C065/14; B29C 65/16 20060101
B29C065/16; B29C 65/48 20060101 B29C065/48 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 13, 2015 |
TW |
104122572 |
Claims
1. An electrochromic device comprising: upper and lower substrate
units, at least one of which is light-transmissive, said upper
substrate unit having an upper substrate body and an upper
electrode formed on said upper substrate body, said lower substrate
unit having a lower substrate body and a lower electrode formed on
said lower substrate body; and an electrochromic laminate
sandwiched between said upper and lower electrodes, and including
an ion storage layer formed on said upper electrode, and having a
first inner surface which is opposite to said upper electrode, and
which includes a first central region and a first peripheral
region, an active layer which is made of an electrochromic
material, which is formed on said lower electrode, and which has a
second inner surface that is opposite to said lower electrode, and
that includes a second central region and a second peripheral
region, a polymer electrolyte which is sandwiched between said
first inner surface of said ion storage layer and said second inner
surface of said active layer, and which is made from a polymeric
adhesive material such that said active layer and said ion storage
layer are bonded to each other by means of said polymer
electrolyte, wherein at least one of said first and second
peripheral regions is roughened to increase a contact area between
said polymer electrolyte and said at least one of said first and
second peripheral regions such that an adhesion force generated
therebetween is effective to minimize thermal shrinkage of said
polymer electrolyte caused by internal stress of said polymer
electrolyte.
2. The electrochromic device according to claim 1, wherein each of
said first and second peripheral regions is roughened.
3. The electrochromic device according to claim 2, wherein each of
said first and second peripheral regions is roughened to form a
plurality of blind holes therein.
4. The electrochromic device according to claim 3, wherein said
blind holes are formed using a laser beam.
5. The electrochromic device according to claim 4, wherein each of
said blind holes has a depth ranging from 200 nm to 2000 nm.
6. The electrochromic device according to claim 3, wherein, in each
of said first and second peripheral regions, a center-to-center
distance between two adjacent ones of said blind holes ranges from
0.05 mm to 0.5 mm.
7. The electrochromic device according to claim 3, wherein each of
said first and second peripheral regions has a width ranging from
0.5 mm to 5 mm.
8. A process for making an electrochromic device, comprising steps
of: (a) preparing upper and lower substrate units, at least one of
which is light-transmissive, the upper substrate unit having an
upper substrate body and an upper electrode formed on the upper
substrate body, the lower substrate unit having a lower substrate
body and a lower electrode formed on the lower substrate body; (b)
forming on the upper electrode an ion storage layer which has a
first inner surface that is opposite to the upper electrode, and
that includes a first central region and a first peripheral region;
(c) forming on the lower electrode an active layer which is made of
an electrochromic material, and which has a second inner surface
that is opposite to the lower electrode, and that includes a second
central region and a second peripheral region; and (d) disposing
between the first and second inner surfaces a polymer electrolyte
made from a polymeric adhesive material such that the active layer
and the ion storage layer are bonded to each other by means of the
polymer electrolyte, wherein the process further comprises, before
step (d), a step (c1) of roughening at least one of the first and
second peripheral regions to increase a contact area between the
polymer electrolyte and the at least one of the first and second
peripheral regions such that an adhesion force generated
therebetween is effective to minimize thermal shrinkage of the
polymer electrolyte caused by internal stress of the polymer
electrolyte.
9. The process according to claim 8, wherein, in step (c1), each of
the first and second peripheral regions is roughened.
10. The process according to claim 9, wherein each of the first and
second peripheral regions is roughened to form a plurality of blind
holes therein.
11. The process according to claim 10, wherein each of the blind
holes is formed by irradiating a corresponding one of the first and
second peripheral regions with a laser beam having a power ranging
from 4 w to 20 w for a laser pulse duration ranging from 0.1 ms to
0.5 ms.
12. The process according to claim 11, wherein each of the blind
holes has a depth ranging from 200 nm to 2000 nm.
13. The process according to claim 12, wherein, in each of the
first and second peripheral regions, a center-to-center distance
between two adjacent ones of the blind holes ranges from 0.05 mm to
0.5 mm.
14. The process according to claim 10, wherein each of the first
and second peripheral regions has a width ranging from 0.5 mm to 5
mm.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Taiwanese application
no. 104122572, filed on Jul. 13, 2015.
FIELD
[0002] The disclosure relates to an electrochromic device, more
particularly to an electrochromic device and a process for making
the same.
BACKGROUND
[0003] An electrochromic device is capable of varying its light
transmission in response to a voltage applied between two
electrodes on the device, and can be used for applications such as
mirrors or windows of vehicles, buildings, etc. As shown in FIGS. 1
and 2, a conventional electrochromic device includes two glass
substrates 15, two transparent electrodes 14 formed respectively on
the glass substrates 15, and an electrochromic laminate sandwiched
between the two transparent electrodes 14. The electrochromic
laminate includes an active layer 12, an ion storage layer 13, and
a polymer electrolyte 11 sandwiched between the active layer 12 and
the ion storage layer 13. The polymer electrolyte 11 includes an
adhesive material and thus can bond the active layer 12 and the ion
storage layer 13 together. The active layer 12 is made of an
electrochromic material, such as tungsten trioxide (WO.sub.3). The
ion storage layer 13 is made of a material which can undergo
reversible oxidation and reduction reactions, such as nickel oxide.
The transparent electrodes 14 are made of, for example, indium tin
oxide.
[0004] Due to generation of internal stress of the polymer
electrolyte 11 resulting possibly from irradiation of ambient light
or changes in temperature of the electrochromic device in use, the
polymer electrolyte 11 may suffer from thermal shrinkage after a
period of use. The conventional electrochromic device thus may have
a plurality of undesirable shrinkage lines 17 at its periphery 16
as shown in FIGS. 1 and 2. Although the polymer electrolyte 11 may
have an increased thickness to address such problem, the
electrochromic device with a thick polymer electrolyte 11 would
have a slow response speed in response to a voltage applied between
the transparent electrodes 14.
SUMMARY
[0005] Therefore, an object of the disclosure is to provide a novel
electrochromic device in which a polymer electrolyte is less likely
to be subjected to the thermal shrinkage, and a process for making
the electrochromic device.
[0006] According to a first aspect of the disclosure, an
electrochromic device includes upper and lower substrate units and
an electrochromic laminate. At least one of the upper and lower
substrate units is light-transmissive. The upper substrate unit has
an upper substrate body and an upper electrode formed on the upper
substrate body. The lower substrate unit has a lower substrate body
and a lower electrode formed on the lower substrate body. The
electrochromic laminate is sandwiched between the upper and lower
electrodes, and includes an ion storage layer, an active layer, and
a polymer electrolyte. The ion storage layer is formed on the upper
electrode, and has a first inner surface which is opposite to the
upper electrode, and which includes a first central region and a
first peripheral region. The active layer is made of an
electrochromic material, is formed on the lower electrode, and has
a second inner surface that is opposite to the lower electrode, and
that includes a second central region and a second peripheral
region. The polymer electrolyte is sandwiched between the first
inner surface of the ion storage layer and the second inner surface
of the active layer, and is made from a polymeric adhesive material
such that the active layer and the ion storage layer are bonded to
each other by means of the polymer electrolyte. At least one of the
first and second peripheral regions is roughened to increase a
contact area between the polymer electrolyte and the at least one
of the first and second peripheral regions such that an adhesion
force generated therebetween is effective to minimize thermal
shrinkage of the polymer electrolyte caused by internal stress of
the polymer electrolyte.
[0007] According to a second aspect of the disclosure, a process
for making an electrochromic device includes steps of:
[0008] (a) preparing upper and lower substrate units, at least one
of which is light-transmissive, the upper substrate unit having an
upper substrate body and an upper electrode formed on the upper
substrate body, the lower substrate unit having a lower substrate
body and a lower electrode formed on the lower substrate body;
[0009] (b) forming on the upper electrode an ion storage layer
which has a first inner surface that is opposite to the upper
electrode, and that includes a first central region and a first
peripheral region;
[0010] (c) forming on the lower electrode an active layer which is
made of an electrochromic material, and which has a second inner
surface that is opposite to the lower electrode, and that includes
a second central region and a second peripheral region; and
[0011] (d) disposing between the first and second inner surfaces a
polymer electrolyte made from a polymeric adhesive material such
that the active layer and the ion storage layer are bonded to each
other by means of the polymer electrolyte, wherein
[0012] the process further comprises, before step (d), a step (c1)
of roughening at least one of the first and second peripheral
regions to increase a contact area between the polymer electrolyte
and the at least one of the first and second peripheral regions
such that an adhesion force generated therebetween is effective to
minimize thermal shrinkage of the polymer electrolyte caused by
internal stress of the polymer electrolyte.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Other features and advantages of the disclosure will become
apparent in the following detailed description of the embodiment
with reference to the accompanying drawings, in which:
[0014] FIG. 1 is a schematic cross-sectional view of a conventional
electrochromic device;
[0015] FIG. 2 is a schematic top view of the conventional
electrochromic device;
[0016] FIG. 3 is a schematic view illustrating inner surfaces of an
ion storage layer and an active layer of an electrochromic device
according to an embodiment of the disclosure;
[0017] FIG. 4 is a schematic fragmentary cross-sectional view of
the electrochromic device according to the disclosure;
[0018] FIG. 5 is a schematic enlarged view illustrating peripheral
regions of the inner surfaces of the ion storage layer and the
active layer;
[0019] FIG. 6 is a block diagram illustrating a process for making
the electrochromic device according to the disclosure; and
[0020] FIG. 7 is a flow diagram illustrating the process for making
the electrochromic device according to the disclosure.
DETAILED DESCRIPTION
[0021] With reference to FIGS. 3 and 4, an electrochromic device
according to an embodiment of the disclosure includes an
electrochromic laminate 2 and upper and lower substrate units 3, 4.
At least one of the upper and lower substrate units 3, 4 is
light-transmissive. In this embodiment, both of the upper and lower
substrate units 3, 4 are light-transmissive. It should be noted
that the drawings, which are for illustrative purposes only, are
not drawn to scale, and are not intended to represent the actual
sizes or actual relative sizes of the components of the
electrochromic device.
[0022] The upper substrate unit 3 has an upper substrate body 32
and an upper electrode 31 formed on the upper substrate body 32. In
this embodiment, the upper substrate body 32 is made of glass, and
the upper electrode 31 is made of indium tin oxide and may have a
thickness ranging from 50 nm to 200 nm.
[0023] The lower substrate unit 4 has a lower substrate body 42 and
a lower electrode 41 formed on the lower substrate body 42. In this
embodiment, the lower substrate body 42 is made of glass, and the
lower electrode 41 is made of indium tin oxide and may have a
thickness ranging from 50 nm to 200 nm.
[0024] The electrochromic laminate 2 is sandwiched between the
upper and lower electrodes 31, 41, and includes an ion storage
layer 33, an active layer 43, and a polymer electrolyte 20.
[0025] The ion storage layer 33 is formed on the upper electrode
31, and has a first inner surface 34 opposite to the upper
electrode 31. The first inner surface 34 includes a first central
region 341 and a first peripheral region 342 surrounding the first
central region 341.
[0026] The active layer 43 is made of an electrochromic material,
is formed on the lower electrode 41, and has a second inner surface
44 opposite to the lower electrode 41. The second inner surface 44
includes a second central region 441 and a second peripheral region
442 surrounding the second central region 441.
[0027] In this embodiment, the active layer 43 is a layer of
cathodic electrochromic material, such as tungsten trioxide, and
may have a thickness ranging from 300 nm to 2300 nm. The ion
storage layer 33 is a layer of anodic electrochromic material, such
as nickel oxide, and may have a thickness ranging from 300 nm to
2300 nm.
[0028] The polymer electrolyte 20 is sandwiched between the first
inner surface 34 of the ion storage layer 33 and the second inner
surface 44 of the active layer 43, and is made from a polymeric
adhesive material such that the active layer 43 and the ion storage
layer 33 are bonded to each other by means of the polymer
electrolyte 20. The polymeric adhesive material may include any
suitable components, as long as the polymer electrolyte 20 made
from the polymeric adhesive material can function as a binder and
an electrolyte. For example, the polymeric adhesive material may
include UV-curable monomers, a plasticizer, a photoinitiator, and
an electrolyte salt.
[0029] At least one of the first and second peripheral regions 342,
442 is roughened to increase a contact area between the polymer
electrolyte 20 and the at least one of the first and second
peripheral regions 342, 442 such that an adhesion force generated
therebetween is effective to minimize thermal shrinkage of the
polymer electrolyte 20 caused by internal stress of the polymer
electrolyte 20. The internal stress of the polymer electrolyte 20
may result from irradiation of ambient light or changes in
temperature of the electrochromic device in use.
[0030] With reference to FIGS. 4 and 5, each of the first and
second peripheral regions 342, 442 is roughened to form a plurality
of blind holes 345, 445 therein. The blind holes 345, 445 are
formed using a laser beam.
[0031] The blind holes 345, 445 have a depth (D2, D4) ranging from
200 nm to 2000 nm, preferably from 200 nm to 800 nm. If the depth
(D2, D4) of the blind holes 345, 445 is not deep enough, the
adhesion force generated among the polymer electrolyte 20 and the
first and second peripheral regions 342, 442 is not effective to
minimize thermal shrinkage of the polymer electrolyte 20. If the
blind holes 345, 445 are too deep and penetrate the ion storage
layer 33 and the active layer 43, respectively, breakage of the ion
storage layer 33 and/or the active layer 43 may result, which may
adversely affect the function of the upper and lower electrodes 31,
41, thereby slowing down the response of the ion storage layer 33
and the active layer 43 to a voltage applied between the upper and
lower electrodes 31, 41.
[0032] A center-to-center distance (D1) between two adjacent ones
of the blind holes 345 in the roughened first peripheral region 342
ranges from 0.05 mm to 0.5 mm, preferably from 0.1 mm to 0.2 mm. A
center-to-center distance (D3) between two adjacent ones of the
blind holes 445 in the roughened second peripheral region 442
ranges from 0.05 mm to 0.5 mm, preferably from 0.1 mm to 0.2 mm. If
the center-to-center distances (D1, D3) are too large, the adhesion
force generated among the polymer electrolyte 20 and the first and
second peripheral regions 342, 442 is not effective to minimize
thermal shrinkage of the polymer electrolyte 20. If the
center-to-center distances (D1, D3) are too small, the mechanical
properties of the first peripheral region 342 of the ion storage
layer 33 and the second peripheral region 442 of the active layer
43 may be adversely affected.
[0033] With reference to FIG. 3, each of the roughened first and
second peripheral regions 342, 442 has a width (W1, W2, W3, W4, W5,
and W6) ranging from 0.5 mm to 5 mm, preferably from 2.5 mm to 3.5
mm. If the width (W1, W2, W3, W4, W5, and W6) is too small, the
adhesion force generated among the polymer electrolyte 20 and the
first and second peripheral regions 342, 442 is not effective to
minimize thermal shrinkage of the polymer electrolyte 20. If the
width (W1, W2, W3, W4, W5, and W6) is too large, the effective area
of the electrochromic device, i.e., the areas of the first and
second central regions 341, 441, is diminished.
[0034] A process for making the electrochromic device according to
the embodiment of the disclosure will be described with reference
to FIGS. 4, 6, and 7. The process includes steps (a) to (d).
[0035] In step (a), the upper and lower substrate units 3, 4 are
prepared.
[0036] In step (b), the ion storage layer 33 is formed on the upper
electrode 31 of the upper substrate unit 3. The ion storage layer
33 has the first inner surface 34 including the first central
region 341 and the first peripheral region 342.
[0037] In step (c), the active layer 43 is formed on the lower
electrode 41 of the lower substrate unit 4. The active layer 43 has
the second inner surface 44 including the second central region 441
and the second peripheral region 442.
[0038] In step (d), the polymer electrolyte 20 is disposed between
the first inner surface 34 of the ion storage layer 33 and the
second inner surface 44 of the active layer 43, and is made from
the polymeric adhesive material such that the active layer 43 and
the ion storage layer 33 are bonded to each other by means of the
polymer electrolyte 20.
[0039] Before step (d), the process further includes a step (c1) of
roughening at least one of the first and second peripheral regions
342, 442 to increase a contact area between the polymer electrolyte
20 and the at least one of the first and second peripheral regions
342, 442 such that an adhesion force generated therebetween is
effective to minimize thermal shrinkage of the polymer electrolyte
20 caused by internal stress of the polymer electrolyte 20.
[0040] In this embodiment, each of the first and second peripheral
regions 342, 442 is roughened to form the blind holes 345, 445
therein. All or some of the blind holes 345, 445 may be selectively
filled with the material of the polymer electrolyte 20. Each of the
blind holes 345, 445 is formed by irradiating a corresponding one
of the first and second peripheral regions 342, 442 with a laser
beam having a power ranging from 4 w to 20 w for a laser pulse
duration ranging from 0.1 ms to 0.5 ms.
[0041] The embodiment of the disclosure will now be explained in
more detail below by way of the following Example 1 and Comparative
Example 1.
EXAMPLE 1
[0042] An electrochromic device was made according to the above
described process. Each of the upper and lower substrate units 3,
4, the ion storage layer 33, the active layer 43, and the polymer
electrolyte 20 had a rectangular shape and a dimension of 134.8
mm.times.78.7 mm. Each of the upper and lower substrate bodies 32,
42 was made of glass. Each of the upper and lower electrodes 31, 41
was made of indium tin oxide and had a thickness of 70 nm.
[0043] The ion storage layer 33 was made of nickel oxide and had a
thickness of 650 nm. The active layer 43 was made of tungsten
trioxide and had a thickness of 800 nm. As shown in FIG. 3, the
first peripheral region 342 on the ion storage layer 33 had two
long-side areas 343 and two short-side areas 344. Each of the
long-side areas 343 had a width (W1) of 2.5 mm. One of the
short-side areas 344 had a width (W2) of 2.5 mm, and the other of
the short-side areas 344 had a width (W3) of 3.5 mm. The second
peripheral region 442 on the active layer 43 had two long-side
areas 443 and two short-side areas 444. The long-side areas 443 had
a width (W4) of 2.5 mm. One of the short-side areas 444 had a width
(W5) of 2.5 mm, and the other of the short-side areas 444 had a
width (W6) of 3.5 mm.
[0044] The blind holes 345 formed in first peripheral region 342 of
the ion storage layer 33 had a depth (D2) of 600 nm, and the
center-to-center distance (D1) between two adjacent ones of the
blind holes 345 was 0.1 mm. The blind holes 445 formed in the
second peripheral region 442 of the active layer 43 had a depth
(D4) of 600 nm, and the center-to-center distance (D3) between two
adjacent ones of the blind holes 445 was 0.1 mm. Each of the blind
holes 345, 445 was formed in the ion storage layer 33 by
irradiating a corresponding one of the first and second peripheral
regions 342, 442 with a laser beam having a power of 10 w for a
laser pulse duration of 0.5 ms.
[0045] The polymer electrolyte 20 (T1) was made from a material
including UV/Visible adhesive (Loctite.RTM. 3321.TM., Henkel Taiwan
Ltd.) and electrolyte salts, and had a thickness of 100 .mu.m.
COMPARATIVE EXAMPLE 1
[0046] An electrochromic device was prepared by a process similar
to the process for making the electrochromic device of Example 1,
except that the blind holes 345, 445 were not formed.
[0047] Reliabilities of the electrochromic devices of Example 1 and
Comparative Example 1 were determined by a thermal shock test for
10 cycles. For each cycle, each of the electrochromic devices was
heated to and maintained at 85.degree. C. for 1 hour, cooled to and
maintained at 25.degree. C. for 0.5 hour, further cooled to and
maintained at -30.degree. C. for 1 hour, and then heated to and
maintained at 25.degree. C. for 0.5 hour. After the thermal shock
test, it could be observed that the polymer electrolyte in the
electrochromic device of Example 1 shrank inwardly for 0.1 mm, and
that the polymer electrolyte in the electrochromic device of
Comparative Example 1 shrank inwardly for 10 mm. It is evident that
the provision of the blind holes 345, 445 in the electrochromic
device is effective to minimize thermal shrinkage of the polymer
electrolyte.
[0048] While the disclosure has been described in connection with
what is considered the exemplary embodiment, it is understood that
this disclosure is not limited to the disclosed embodiment but is
intended to cover various arrangements included within the spirit
and scope of the broadest interpretation so as to encompass all
such modifications and equivalent arrangements.
* * * * *