Polyelectrolyte and energy storage device
09590269 ยท 2017-03-07
Assignee
Inventors
- Chung-Hsiang Chao (Hsinchu, TW)
- Li-Duan Tsai (Hsinchu, TW)
- Chia-Chen Fang (Taipei, TW)
- Chih-Ching Chang (Hsinchu, TW)
- Chi-Yang Chao (Taipei, TW)
- Kun-Lin Liu (Taipei, TW)
Cpc classification
C08F8/34
CHEMISTRY; METALLURGY
H01G11/62
ELECTRICITY
C08F8/34
CHEMISTRY; METALLURGY
Y02E60/10
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y02E60/50
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y02E60/13
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
C08F8/34
CHEMISTRY; METALLURGY
C08F212/14
CHEMISTRY; METALLURGY
Abstract
A polyelectrolyte includes a first segment and a second segment, wherein the structure of the first segment is at least one of formula (1) and formula (2); the structure of the second segment is at least one of formula (3) and formula (4). The polyelectrolyte undergoes microphase separation to form a nanoscale ordered self-assembled microstructure. ##STR00001##
Claims
1. A polyelectrolyte, comprising a first segment and a second segment, wherein a structure of the first segment is formula (2): ##STR00040## in formula (2), R.sub.9 to R.sub.11 are each independently H, F, or ##STR00041## R.sub.12 is ##STR00042## R.sub.13 is ##STR00043## R.sub.14 is H, ##STR00044## or CN, n=1 to 10, y=1 to 1000; a structure of the second segment is at least one of formula (3) and formula (4): ##STR00045## in formula (3), R.sub.15 to R.sub.17 are each independently H, F, or ##STR00046## R.sub.18 to R.sub.19 are each independently ##STR00047## R.sub.20 is SO.sub.3.sup.M.sup.+, PO.sub.4.sup.M.sup.+, or COO.sup.M.sup.+, n=1 to 10, M.sup.+ is H.sup.+, Li.sup.+, Na.sup.+, or K.sup.+, p=1 to 500; ##STR00048## in formula (4), R.sub.21 to R.sub.23 are each independently H, F, or ##STR00049## R.sub.24 to R.sub.28 are each independently H, F, ##STR00050## and at least one of R.sub.24 to R.sub.28 is ##STR00051## R.sub.30 is SO.sub.3.sup.M.sup.+, PO.sub.4.sup.M.sup.+, or COO.sup.M.sup.+, n=1 to 10, M.sup.+is H.sup.+, Li.sup.+, Na.sup.+, or K.sup.+, q=1 to 500.
2. The polyelectrolyte of claim 1, wherein the first segment and the second segment are repeated, or arranged in random.
3. The polyelectrolyte of claim 1, wherein a weight average molecular weight of the first segment is between 10,000 and 90,000.
4. The polyelectrolyte of claim 1, wherein a weight average molecular weight of the second segment is between 10,000 and 30,000.
5. The polyelectrolyte of claim 1, wherein a molecular repeating unit y of the first segment is 300 to 900.
6. The polyelectrolyte of claim 1, wherein a molecular repeating unit p or q of the second segment is 50 to 200.
7. The polyelectrolyte of claim 1, wherein an ionic conductivity of the polyelectrolyte is greater than 10.sup.5 S/cm at room temperature and without any solvent or electrolyte.
8. A polyelectrolyte, comprising a first segment, a second segment, and a third segment, and the third segment is between the first segment and the second segment, wherein a structure of the first segment is formula (2): ##STR00052## in formula (2), R.sub.9 to R.sub.11 are each independently H, F, or ##STR00053## R.sub.12 is ##STR00054## R.sub.13 is ##STR00055## R.sub.14 is H, ##STR00056## or CN, n=1 to 10, y=1 to 1000; a structure of the second segment is at least one of formula (3) and formula (4): ##STR00057## in formula (3), R.sub.15 to R.sub.17 are each independently H, F, or ##STR00058## R.sub.18 to R.sub.19 are each independently ##STR00059## R.sub.20 is SO.sub.3.sup.M.sup.+, PO.sub.4 .sup.M.sup.+, or COO.sup.M.sup.+, n=1 to 10, M.sup.+ is H.sup.+, Li.sup.+, Na.sup.+, or K.sup.+, p=1 to 500; ##STR00060## in formula (4), R.sub.21 to R.sub.23 are each independently H, F, or ##STR00061## R.sub.24 to R.sub.28 are each independently H, F, ##STR00062## and at least one of R.sub.24 to R.sub.28 is ##STR00063## R.sub.29 is ##STR00064## R.sub.30 is SO.sub.3.sup.M.sup.+, PO.sub.4.sup.M.sup.+, or COO.sup.M.sup.+, n=1 to 10, M.sup.+ is H.sup.+, Li.sup.+, Na.sup.+, or K.sup.+, q=1 to 500; a structure of the third segment is formula (5): ##STR00065## in formula (5), R.sub.31 to R.sub.36 are each independently H, F, or ##STR00066## n=1 to 10, w=1 to 500.
9. The polyelectrolyte of claim 8, wherein the first segment, the second segment, and the third segment are repeated, or arranged in random.
10. The polyelectrolyte of claim 8, wherein a weight average molecular weight of the first segment is between 10,000 and 90,000.
11. The polyelectrolyte of claim 8, wherein a weight average molecular weight of the second segment is between 10,000 and 30,000.
12. The polyelectrolyte of claim 8, wherein a weight average molecular weight of the third segment is between 10,000 and 20,000.
13. The polyelectrolyte of claim 8, wherein a molecular repeating unit y of the first segment is 300 to 900.
14. The polyelectrolyte of claim 8, wherein a molecular repeating unit p or q of the second segment is 50 to 200.
15. The polyelectrolyte of claim 8, wherein a molecular repeating unit w of the third segment is 100 to 400.
16. The polyelectrolyte of claim 8, wherein an ionic conductivity of the polyelectrolyte is greater than 10.sup.5 S/cm at room temperature and without any solvent or electrolyte.
17. An energy storage device, comprising the polyelectrolyte of claim 1, wherein the polyelectrolyte is applied within the energy storage device via mixing, coating, covering, or adding.
18. The energy storage device of claim 17, wherein the energy storage device comprises a lithium ion primary battery, a lithium ion secondary battery, a capacitor, a supercapacitor, a fuel cell, a metal-sulfur battery, or a metal-air battery.
19. The energy storage device of claim 17, further comprising a plasticizer added in the polyelectrolyte.
20. The energy storage device of claim 19, wherein the plasticizer comprises bis(2-ethylhexyl)phthalate (BEHP), dibutyl phthalate (DBP), or diisobutyl phthalate (DIBP).
21. The energy storage device of claim 17, further comprising a liquid electrolyte added in the polyelectrolyte.
22. The energy storage device of claim 17, further comprising a solvent added in the polyelectrolyte, wherein the solvent comprises propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DEC), or ethyl methyl carbonate (EMC).
23. The energy storage device of claim 21, wherein the liquid electrolyte comprises a solvent and a lithium salt dissolved in the solvent, wherein the solvent comprises propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DEC), or ethyl methyl carbonate (EMC).
24. The energy storage device of claim 23, wherein the lithium salt comprises LiPF.sub.6, LiBF.sub.4, LiClO.sub.4, or LiTFSI.
25. An energy storage device, comprising the polyelectrolyte of claim 8, wherein the polyelectrolyte is applied within the energy storage device via mixing, coating, covering, or adding.
26. The energy storage device of claim 25, wherein the energy storage device comprises a lithium ion primary battery, a lithium ion secondary battery, a capacitor, a supercapacitor, a fuel cell, a metal-sulfur battery, or a metal-air battery.
27. The energy storage device of claim 25, further comprising a plasticizer added in the polyelectrolyte.
28. The energy storage device of claim 27, wherein the plasticizer comprises bis(2-ethylhexyl)phthalate (BEHP), dibutyl phthalate (DBP), or diisobutyl phthalate (DIBP).
29. The energy storage device of claim 25, further comprising a liquid electrolyte added in the polyelectrolyte.
30. The energy storage device of claim 25, further comprising a solvent added in the polyelectrolyte, wherein the solvent comprises propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DEC), or ethyl methyl carbonate (EMC).
31. The energy storage device of claim 29, wherein the liquid electrolyte comprises a solvent and a lithium salt dissolved in the solvent, wherein the solvent comprises propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DEC), or ethyl methyl carbonate (EMC).
32. The energy storage device of claim 31, wherein the lithium salt comprises LiPF.sub.6, LiBF.sub.4, LiClO.sub.4, or LiTFSI.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS
(15) A polyelectrolyte of the disclosure includes a first segment and a second segment, wherein the structure of the first segment is at least one of formula (1) and formula (2); and the structure of the second segment is at least one of formula (3) and formula (4). The molecular weight (M.sub.W) of the first segment is, for instance, between 10,000 and 90,000; the molecular weight of the second segment is, for instance, between 10,000 and 30,000.
(16) ##STR00018##
(17) In formula (1), R.sub.1 to R.sub.8 are each independently H, F, or
(18) ##STR00019##
n=1 to 10, x=1 to 1000. Moreover, the molecular repeating unit x of the first segment is preferably 300 to 900.
(19) ##STR00020##
(20) In formula (2), R.sub.9 to R.sub.11 are each independently H, F, or
(21) ##STR00021##
R.sub.12 is
(22) ##STR00022##
R.sub.13 is
(23) ##STR00023##
R.sub.14 is H,
(24) ##STR00024##
or CN, n=1 to 10, y=1 to 1000. Moreover, the molecular repeating unit y of the first segment is preferably 300 to 900.
(25) ##STR00025##
(26) In formula (3), R.sub.15 to R.sub.17 are each independently H, F, or
(27) ##STR00026##
R.sub.18 to R.sub.19 are each independently
(28) ##STR00027##
R.sub.20 is SO.sub.3.sup.M.sup.+, PO.sub.4.sup.M.sup.+, or COO.sup.M.sup.30 , n=1 to 10, M.sup.+ is H.sup.+, Li.sub.+, Na.sup.+, or K.sup.+, p=1 to 500. The molecular repeating unit p of the second segment is preferably 50 to 200.
(29) ##STR00028##
(30) In formula (4), R.sub.21 to R.sub.23 are each independently H, F, or
(31) ##STR00029##
R.sub.24 to R.sub.28 are each independently H, F,
(32) ##STR00030##
and at least one of R.sub.24 to R.sub.28 is
(33) ##STR00031##
R.sub.29 is
(34) ##STR00032##
R.sub.30 is SO.sub.3.sup.M.sup.+, PO.sub.4.sup.M.sup.+, or COO.sup.M.sup.+, n=1 to 10, M.sup.+ is H.sup.+, Li.sup.+, Na.sup.+, or K.sup.+, q=1 to 500. The molecular repeating unit q of the second segment is preferably 50 to 200.
(35) In the present embodiment, the first segment is responsible for providing mechanical strength and water- and oxygen-blocking properties to the polyelectrolyte, and the structure of formula (1) or the structure of formula (2) can be selected, or the first segment can have the structures of both formula (1) and formula (2); the second segment is responsible for providing ionic conductivity to the polyelectrolyte, and the structure of formula (3) or the structure of formula (4) can be selected, or the second segment can have the structures of both formula (3) and formula (4). Accordingly, the polyelectrolyte undergoes microphase separation to form a nanoscale ordered self-assembled microstructure.
(36) Another polyelectrolyte of the disclosure includes a third segment between the first segment and the second segment, and the structure of the third segment is formula (5). In the present embodiment, the molecular weight of the third segment is, for instance, between 10000 and 20000.
(37) ##STR00033##
(38) In formula (5), R.sub.31 to R.sub.36 are each independently H, F, or
(39) ##STR00034##
n=1 to 10, w=1 to 500. The molecular repeating unit w of the third segment is preferably 100 to 400.
(40) In the present embodiment, the third segment is between the first segment and the second segment, and the function thereof is to keep the second segment far away from the first segment, such that the second segment is not limited by the first segment. As a result, a greater free swinging space can be obtained, and the ionic conductivity of the polyelectrolyte is thereby increased.
(41) All polyelectrolyte of the disclosure can undergo microphase separation, and thus a nanoscale ordered self-assembled structure can be formed. Moreover, the main structure formed by the first segment within the polyelectrolyte provides mechanical strength and the function of preventing penetration of water and oxygen to the polymer; the ion-conducting channel is responsible for the transfer of ions. The second segment within the polyelectrolyte comprises moiety having a functional group such as sulfonate, phosphate, or carboxylate and covalently bonded on the main chain, and does not move. As a result, ion transference number can be significantly increased. Moreover, since the ions can only move in the nano channel, the formed metal deposit is also limited therein, such that the possibility of puncture by a metal dendrite is reduced.
(42) Moreover, in the polyelectrolyte of the disclosure, it is observed that the addition of a plasticizer, a high-dielectric constant solvent, or a liquid electrolyte of a different proportion also facilitates the increase in ionic conductivity. For instance, the plasticizer may be, for instance, bis(2-ethylhexyl)phthalate (BEHP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), etc. The high-dielectric constant solvent may be, for instance, propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DEC), ethyl methyl carbonate (EMC), etc. The liquid electrolyte may be formed by dissolving an electrolyte (i.e., lithium salt) such as LiPF.sub.6, LiBF.sub.4, LiClO.sub.4, LiTFSI and so on in the high-dielectric constant solvent.
(43) Therefore, for the polyelectrolyte of the disclosure, the ionic conductivity is always greater than 10.sup.5 S/cm at room temperature and without any solvent or electrolyte solution. In the case of adsorption by a small amount of electrolyte solution (<30 wt %), an ionic conductivity of 10.sup.4 S/cm is obtained.
(44)
(45) An energy storage device 100 in
(46) Several examples are described below to verify the efficacy of the disclosure. However, the disclosure is not limited to the following content.
EXAMPLE 1
(47) According to the following synthesis process, 100 l of sec-butyllithium (1.3M in cyclohexane) and 12.88 ml of styrene monomer are added into THF solvent at 78 C., and then the mixture is stirred for 15 minutes. At the same temperature, 4.17 ml of p-tert-butoxystyrene is added. After 3 days, anhydrous methanol is used to stop the reaction. In the meantime, a copolymer of polystyrene and PtBuOS (poly(p-tert-butoxystyrene)) is precipitated.
(48) 12 g of foregoing copolymer is solved in 1,4-dioxane, and 7.1 ml of 37 wt % hydrochloric acid is added. The mixture is heated to 60 C. and stands for 2 days, and then the polymer is precipitated in n-hexane followed by water rinse again and again, so as to obtain a de-protection copolymer of poly(p-hydroxystyrene).
(49) 10 g of the de-protection copolymer is dissolved in THF. After heating to 60 C., 3.6 g of KH is added in the mixture to react for 2 hours. Next, 5.3 g of 1,3-propanesultone is added in the mixture. After 24 hours, the product is cleaned by methanol, and excess TBAOH (tetrabutylammonium hydroxide) and 1.5M sulfuric acid solution are added respectively. After cleaning by 1M LiOH, the resulting polyelectrolyte is obtained.
(50) ##STR00035##
(51) Then, the PS standard product was compared by using gel permeation chromatography (GPC), and it was observed that the molecular weights of the two segments were respectively Mw 90,000 and 30,000 (wherein a and b are estimated to be about 865 and 717 respectively), and a nuclear magnetic resonance apparatus (1H-NMR) also confirmed the proportion of the two segments as shown in
(52) TABLE-US-00001 TABLE 1 Dry film Wet film DBP content Thickness Impregnation (wt %) (m) (10.sup.5 S/cm) (10.sup.5 S/cm) ratio (wt %) 10 185 N/A 1.2 10.8 20 198 N/A 2.4 26.4 30 215 N/A 3.7 27.2 40 222 N/A 4.1 30.8
(53) It can be known from Table 1 that, the ionic conductivity of the wet film is 1.210.sup.5 to 4.110.sup.5S/cm, and the impregnation ratio thereof is 10.8 wt % to 30.8 wt %.
EXAMPLE 2
(54) According to the following synthesis process, 70 l of sec-butyllithium (1.3M in cyclohexane) and 5 ml of styrene monomer are added into THF solvent at 78 C., and then the mixture is stirred for 15 minutes. At the same temperature, 2.67 ml of isoprene monomer is added. The temperature is then risen to 30 C. After 3 days, anhydrous methanol is used to stop the reaction. In the meantime, a copolymer of polystyrene and poly(1, 2 or 3,4-isoprene) is precipitated.
(55) 1.5 g of foregoing copolymer is solved in THF, and 40 ml of 9-borabicyclo(3.3.1)nonane (9-BBN) [0.5M in THF] is added at 15 C. The mixture is heated to 55 C. and stands for 2 days, and then the temperature is cooled down to 25 C. 1 ml of methanol is added to the mixture and then stirred for 30 minutes. 0.46 g of 6N NaOH and 4 ml of 30% H.sub.2O.sub.2 aqueous solution are added in the mixture. After 2 hours, the temperature is risen to 55 C. for 1 hour. After phase separation, the upper level solution is added in to 0.25M NaOH aqueous solution and then precipitated to obtain a copolymer in which the double bonds of isoprene are hydrolyzed into hydroxyl groups.
(56) 0.5 g of the hydrolyzed copolymer is dissolved in THF. After heating to 60 C., 0.6 g of KH is added the mixture to react for 2 hours. Next, 0.37 ml of 1,3-propanesultone is added in the mixture. After 8 hours, the product is cleaned by methanol, and excess TBAOH (tetrabutylammonium hydroxide) and 1.5M sulfuric acid solution are added respectively. After cleaning by 1M LiOH, the resulting polyelectrolyte is obtained (R is CH.sub.3 or H).
(57) ##STR00036##
(58) The PS standard product was compared by using GPC, and it was observed that the molecular weights of the two segments were respectively Mw 50,000 and 20,000 as shown in
(59) TABLE-US-00002 TABLE 2 Mn Mw PDI PS 43716 50349 1.15 SI 52 53646 71762 1.29
(60) Then, a plasticizer DBP in a different amount was added to facilitate forming of film, and then measurement of lithium ionic conductivity was performed on the dry film, and the results are shown in Table 3 below.
(61) TABLE-US-00003 TABLE 3 Dry film DBP content (wt %) Thickness (m) (10.sup.5 S/cm) 0 50 2.8 5 101 4.8 10 95 4.3 15 101 4.0 20 132 4.2
(62) It can be known from Table 3 that, for the polyelectrolyte of example 2, at room temperature and without any plasticizer or electrolyte solution, the ionic conductivity of 2.810.sup.5 S/cm can be achieved. With an addition of 5 wt % to 20 wt % of DBP, the ionic conductivity of the dry film is increased to 4.010.sup.5 S/cm or greater.
(63) Moreover, testing was performed on the polyelectrolyte without a plasticizer to obtain an impregnated-only electrolyte (1M LiClO.sub.4 in EC/PC), wherein the conductivity is increased to 2310.sup.5 S/cm, and the impregnation ratio is 22 wt %.
EXAMPLE 3
(64) According to the following synthesis process, 100 l of sec-butyllithium (1.3M in cyclohexane) and 1.39 ml of p-tert-butoxystyrene monomer are added into THF solvent at 78 C., and then the mixture is stirred for 3 days. At the same temperature, 3.82 ml of isoprene monomer is added. The temperature is then risen to 30 C. After 3 days, anhydrous methanol is used to stop the reaction. In the meantime, a copolymer of poly(p-hydroxy styrene) and poly(1,2 or 3,4-isoprene) is precipitated.
(65) 2 g of foregoing copolymer is dissolved in THF, and 50 ml of 9-borabicyclo(3.3.1)nonane (9-BBN) [0.5M in THF] is added at 15 C. The mixture is heated to 55 C. and stands for 2 days, and then the temperature is cooled down to 25 C. 1 ml of methanol is added to the mixture and then stirred for 30 minutes. 0.5 g of 6N NaOH and 5 ml of 30% H.sub.2O.sub.2 aqueous solution are added in the mixture. After 2 hours, the temperature is risen to 55 C. for 1 hour. After phase separation, the upper level solution is added in to 0.25M NaOH aqueous solution and then precipitated to obtain a copolymer in which the double bonds of isoprene are hydrolyzed into hydroxyl groups.
(66) 2 mmol of the hydrolyzed copolymer is dissolved in THF, and then 2.5 mmol of NaOH is added and stirred for 12 hours. 2.8 mmol of liquid crystal (LC)-containing reactant
(67) ##STR00037##
and 3 mmol of TBAB (tetrabutylammonium bromide) are added, and the temperature is risen to 60 C. After 4 days, the product is cleaned by large amounts of pure water. Afterward, the product is cleaned by methanol, so as to obtain a LC polymer.
(68) 12 g of the LC polymer is solved in 1,4-dioxane, and 9.82 ml of 85 wt % phosphoric acid solution is added at room temperature for 12 hours. The polymer is precipitated in n-hexane followed by water rinse again and again, so as to obtain a de-protection LC polymer.
(69) 10.8 g of the de-protection LC polymer is dissolved in THF. 3.6 g of KH is added in the mixture to react for 1 hour. Next, 5.35 g of 1,3-propanesultone is added in the mixture and then the temperature is risen to 60 C. After 24 hours, the product is cleaned by methanol, and excess TBAOH (tetrabutylammonium hydroxide) is added. After cleaning by 1.5M sulfuric acid solution, the resulting polyelectrolyte is obtained (R is CH.sub.3 or H).
(70) ##STR00038##
(71) The PS standard product was compared by using GPC, and it was observed that the molecular weights of the two segments were respectively Mn 10,000 and 20,000 as shown in
(72) TABLE-US-00004 TABLE 4 Correctional Mn Deg. Of LC Sample code Mn (g/mol) PDI (g/mol) grafting (%) PtBS 10400 1.10 PtBS-b-PI 34221 1.19 20107 PtBS-b-PIOBP 52100 1.21 31000 79 PtBS-b-PIOLCN 73500 1.25 32000 69 PtBS-b-PIOLC.sub.6 81000 1.26 33000 75
(73) Measurement of proton conductivity was performed on the wet film of the polyelectrolyte washed with acid, and the results are shown in Table 5 below.
(74) TABLE-US-00005 TABLE 5 Wet film Terminal Thickness functional group (m) (10.sup.2 S/cm) PIOSCLC 213 1.44 PIOSCLCN 219 2.33 PIOSCLC.sub.6 223 1.01
(75) It can be known from Table 5 that, the proton conductivity of the polyelectrolyte of example 3 is 1.0110.sup.2 S/cm to 2.3310.sup.2 S/cm.
EXAMPLE 4
(76) According to the following synthesis process, 347.9 l of sec-butyllithium (1.3M in cyclohexane) and 20 ml of styrene monomer are added into toluene solvent at room temperature, and then the mixture is stirred for 15 minutes. At the same temperature, 6.65 ml of isoprene monomer is added. The color of the mixture solution changes from deep red to light yellow. After 12 hours, the temperature is cooled down to 78 C., and then 13.28 ml of isoprene monomer are added into THF solvent. When the color of the mixture solution become lighter, the temperature is raised to 30 C. After 4 days, anhydrous methanol is used to stop the reaction. In the meantime, a copolymer of polystyrene, poly(1,4-isoprene) and poly(1,2 or 3,4-isoprene) is precipitated.
(77) 4 g of foregoing copolymer is dissolved in THF, and 100 ml of 9-borabicyclo(3.3.1)nonane (9-BBN) [0.5M in THF] is added at 15 C. The mixture is heated to 55 C. and stands for 2 days, and then the temperature is cooled down to 25 C. 1 ml of methanol is added to the mixture and then stirred for 30 minutes. 2 g of 6N NaOH and 11 ml of 30% H.sub.2O.sub.2 aqueous solution are added in the mixture. After 2 hours, the temperature is risen to 55 C. for 1 hour. After phase separation, the upper level solution is added in to 0.25M NaOH aqueous solution and then precipitated to obtain a copolymer in which the double bonds of isoprene are hydrolyzed into hydroxyl groups.
(78) 1 g of the hydrolyzed copolymer is solved in THF. After heating to 60 C., 0.66 g of KH is added the mixture to react for 2 hours. Next, 0.44 ml of 1,3-propanesultone is added in the mixture. After 8 hours, the product is cleaned by methanol, and excess TBAOH (tetrabutylammonium hydroxide) and 1.5M sulfuric acid solution are added respectively. After cleaning by 1M LiOH aqueous solution, the resulting polyelectrolyte is obtained (R is CH.sub.3 or H).
(79) ##STR00039##
(80) The PS standard product was compared by using GPC, and it was observed that the molecular weights of the three segments were respectively Mw 40,000, 10,000 and 20,000 as shown in
(81) TABLE-US-00006 TABLE 6 Mn Mw PDI PS 37600 40819 1.09 SII 412 75639 90070 1.19
(82) A nuclear magnetic resonance (1H-NMR) apparatus also confirmed the proportion of the three segments as shown in
(83) Then, a plasticizer DBP in a different amount was added. Measurement was respectively performed on the dry film and the wet film soaked in an electrolyte solution (1M LiClO.sub.4 in EC/PC), and the results are shown in Table 7 below.
(84) TABLE-US-00007 TABLE 7 DBP Dry film Wet film content Thickness Impregnation (wt %) (m) (10.sup.5 S/cm) (10.sup.5 S/cm) ratio (wt %) 0 50 4.8 32 10 10 37 1.2 4.5 5.2 20 98 4.8 30 N/A
(85) It can be known from Table 7 that, at room temperature and without any plasticizer or electrolyte, the ionic conductivity is 4.810.sup.5 S/cm; without an additive, the conductivity of the impregnated-only electrolyte is increased to 3.210.sup.4 S/cm, and impregnation ratio is 10 wt %. With an addition of 10 wt % to 20 wt % of DPB, the ionic conductivity of the dry film is 1.210.sup.5 to 4.810.sup.5 S/cm. When a polyelectrolyte containing 20 wt % of DPB was impregnated into an electrolyte, the ionic conductivity is increased to 310.sup.4 S/cm.
EXAMPLE 5
(86) The polyelectrolytes in different proportion of molecular weight are prepared by the same way of example 4 with different feed ratios. The weight-average molecular weights (Mw) of SII-411 segments are 40000, 10000 and 10000 respectively; the Mw of SII-412 segments are 40000, 10000 and 20000 respectively; the Mw of SII-422 segments are 40000, 20000 and 20000 respectively; the Mw of SII-522 are 50000, 20000 and 20000 respectively. The conductivity thereof is shown in Table 8 below.
(87) TABLE-US-00008 TABLE 8 Dry film Wet film Thickness Impregnation (m) (10.sup.5 S cm.sup.1) (10.sup.5 S cm.sup.1) ratio (wt %) SII-411 87 5.3 9.8 8.7 SII-412 67 9.7 10.3 7.6 SII-422 87 12.0 10.2 15.0 SII-522 59 8.1 11.6 20.0
(88) It can be known from Table 8 that, at room temperature and without any plasticizer or electrolyte, the ionic conductivity is 5.310.sup.5 S/cm to 12.010.sup.5 S/cm; without an additive, the conductivity of the impregnated-only electrolyte is increased to 9.810.sup.4 S/cm to 11.610.sup.5 S/cm, and the impregnation ratio is 7.6 wt % to 20 wt %.
(89) Based on the above, the polyelectrolyte provided by the disclosure can reduce or completely omit an electrolyte solution that is readily volatilized and flammable in an energy storage device. Moreover, at room temperature and without any electrolyte, an ionic conductivity of about 10.sup.5 S/cm is still obtained, and in the case of impregnating a small amount of electrolyte, an ionic conductivity of about 10.sup.4 S/cm can be obtained. Such polyelectrolyte can be applied in any electrochemical energy storage device, and can effectively eliminate or reduce the use of an electrolyte, thus significantly increasing the characteristics of the electrochemical energy storage device.
(90) Although the disclosure has been described with reference to the above embodiments, it will be apparent to one of the ordinary skill in the art that modifications to the described embodiments may be made without departing from the spirit of the disclosure. Accordingly, the scope of the disclosure is defined by the attached claims not by the above detailed descriptions.