CN106684443A - Preparation method for modified graphene oxide-doped solid polymer electrolyte - Google Patents
Preparation method for modified graphene oxide-doped solid polymer electrolyte Download PDFInfo
- Publication number
- CN106684443A CN106684443A CN201610626282.5A CN201610626282A CN106684443A CN 106684443 A CN106684443 A CN 106684443A CN 201610626282 A CN201610626282 A CN 201610626282A CN 106684443 A CN106684443 A CN 106684443A
- Authority
- CN
- China
- Prior art keywords
- polymer electrolyte
- graphene oxide
- hours
- preparation
- modified graphene
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
-
- Y—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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Dispersion Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a preparation method for a modified graphene oxide-doped solid polymer electrolyte. The preparation method specifically comprises the steps of doping the prepared modified graphene oxide into a mixed solution of polyoxyethylene and polyvinyl alcohol, then adding a perchloric acid lithium salt, performing a solution casting method, pouring the mixed solution into a polytetrafluoroethylene die, and drying the solvent at a normal temperature and in a vacuum drying oven to obtain a polymer electrolyte film. The prepared polymer electrolyte, due to the existence of ether oxygen bonds on the modified graphene oxide, can promote dissociation of the lithium salt and improve ionic conductivity of the polymer electrolyte; meanwhile, the crystalline region of polyoxyethylene can be suppressed by polyvinyl alcohol while the mechanical strength and ionic conductivity of the polymer electrolyte can be strengthened; and the prepared polymer electrolyte has relatively high ionic conductivity, relatively high mechanical strength and high safety performance.
Description
Technical field
The invention belongs to the preparation of cell art, specially progress of solid polymer electrolyte for Li-ion batteries.
Background technology
Lithium ion battery is because energy density is high, specific capacity is big, light weight the advantages of be widely used in mobile communication such as mobile phone,
On laptop computer, video camera, game machine, electric tool and power vehicle power supply, these applications are accompanied with the life moment of people,
Therefore the security performance of battery receives people and more and more pays close attention to, and is gradually changed to the important mark that people investigate battery performance
It is accurate.Additionally, organic solvent of the electrolyte of lithium ion battery all containing low-flash, low ignition point, inflammable and explosive, battery is short
Road, overcharge, be heated, being clashed etc. under extreme case that easily catching fire even explodes, so as to give the life of lithium ion battery
Produce, transport and using potential safety hazard is brought, also seriously constrain it and be particularly in electric automobile field in some fields
Popularization and application.Therefore, people look on the bright side of things send out solid polymer electrolyte replacement liquid organic electrolyte always.Masuda Y etc. use poly-
Ethylene glycol and aluminic acid reactant salt generate Polyethylene Glycol-Aluminate, with double trifluoromethanesulfonimide lithium formation of solid polycomplex electrolyte 30
DEG C when electrical conductivity reach 10-4The S/cm orders of magnitude, and the electrolyte electrochemical stability window has 4.5V, can substantially meet battery
Application requirement.(Masuda Y, Seki M, Nakayama M, et al. Study on ionic conductivity of
Polymer electrolyte plasticized with PEG-aluminates ester for rechargeable
lithium ion battery[J].Solid State Ionics,2006,177(9-10):843-846).Lee etc. is utilized
SiO2It is compound with α-methyl styrene also to obtain preferable effect.（K.H.Lee, Y.G.Lee, J.K.Park, et al.
Effect of silica on the electrochemical characteristics of the plasticized
polymer electrolytes based on the P(AN-co-MMA)copolymer[J]. Solid State
Ionics,2000,133:257-263）.Relative to liquid organic electrolyte, solid polymer electrolyte has following several respects
Advantage：1st, safety is good：Polymer dielectric is structure of whole solid state, and polymer is nonflammable, and more resistant to impact without leakage
Danger, the even potential safety hazard such as blast of not burning when using.2nd, encapsulation process performance is good：In solid polymer electrolyte not
Need to use barrier film, battery structure is more simplified, design more flexible, than liquid electrolyte encapsulation is more easy to, can be according to battery request
Processing is prepared into variously-shaped even ultra-thin membranaceous, further increases the volume energy density of lithium battery；3rd, electrode is stable
Property is good：Polymer dielectric inhibits the generation that electrode attachment dendroid lithium is crystallized during circulating battery, makes circulating battery
Efficiency will not be reduced, and more be not in internal short-circuit of battery problem.
The content of the invention
Subject matter to be solved by this invention is：Due to lithium ion battery common electrolyte mostly be ethylene carbonate,
The organic electrolytes such as diethyl carbonate, the presence of these electrolyte can make lithium ion constantly heavy on negative pole in reduction process
Product, forms Li dendrite, pierces through barrier film, causes the short circuit of battery；Polymer dielectric is used for into lithium ion battery, liquid can be excluded
The problem of electrolyte easily leakage, replaces the isolating membrane in battery, suppresses the generation of electrode surface dendrite, reduces electrolyte and electrode
Reactivity, improve the specific energy of battery, make battery that there is pressure, impact resistance, low production cost and easily processed into type.
To solve above-mentioned technical problem, the technical scheme is that：A kind of solid of modified graphene oxide doping gathers
The preparation method of polymer electrolyte, including step：
（1）0.1~1g graphene oxides are added to into 50~100mlN, in dinethylformamide, 20~40 points of ultrasonic disperse
Clock, forms homodisperse graphene oxide mixed solution, measures 10~30ml thionyl chlorides and is added to obtained graphite oxide
In alkene mixed solution, react 12~36 hours in 50~80 DEG C under mechanical agitation, be then centrifuged for, wash, be dried；
（2）By step（1）Gained sample and Polyethylene Glycol are added in 10~20ml dimethyl sulphoxide solutions, at 50~70 DEG C and
React 48~72 hours under nitrogen atmosphere, be then centrifuged for, wash, being dried；
（3）Polyethylene glycol oxide and polyvinyl alcohol are mixed by certain mass ratio, mechanical agitation 4~6 hours at 40~60 DEG C；
（4）By step（2）Gained sample is added to step（3）Mixed liquor in, stirring 4~6 hours after, add corresponding lithium
Salt, continues to stir 5~8 hours at room temperature, then pours mixed liquor in Teflon mould into, and 12 are dried in fume hood
Hour, place in vacuum drying oven and be dried 24 hours.
Above-mentioned steps（2）Described Polyethylene Glycol consumption is 20~30 times of graphene oxide quality.
Above-mentioned steps（3）The described polyethylene glycol oxide is 9~7 with the mass ratio of polyvinyl alcohol:1~3.
Above-mentioned steps（4）Described lithium salts is in lithium perchlorate, double trifluoromethanesulfonimide lithiums, dioxalic acid lithium borate
At least one, the consumption of wherein lithium salts accounts for the 5%~20% of polyethylene glycol oxide and polyvinyl alcohol quality.
Above-mentioned steps（4）Described sample quality accounts for the 5~15% of polyethylene glycol oxide and polyvinyl alcohol quality.
The present invention is a kind of preparation method of the solid polymer electrolyte of modified graphene oxide doping, with following excellent
Point：
1st, the Mi Yang functional groups that modified graphene oxide contains can interact with lithium salts, promote the dissolving of lithium salts, so as to carry
The ionic conductivity of high polymer electrolyte；
2nd, the blending of polyvinyl alcohol and polyethylene glycol oxide, on the one hand suppresses the crystal region of polyethylene glycol oxide, improves polyoxyethylene
The sub-chain motion ability of alkene, strengthens the conductivity and mechanical strength of polymer dielectric；On the other hand, in polyvinyl alcohol segments
Carbon-oxygen bond can promote the dissolving of alkali metal salt, improve ionic conductivity；
3rd, the generation of electrode surface dendrite can effectively be suppressed as the pathway of lithium ion using solid polymer electrolyte,
Prevent dendrite from piercing through barrier film, cause the danger of battery short circuit.
Specific embodiment
Further description is made to the above of the present invention below by way of specific embodiment, but this should not be managed
Solve and be only limitted to following examples for present disclosure.
Embodiment one：
（1）0.1g graphene oxides are added to into 20mlN, in dinethylformamide, ultrasonic disperse 30 minutes forms uniform point
Scattered graphene oxide mixed solution, measures 10ml thionyl chlorides and is added in obtained graphene oxide mixed solution, machinery
React 24 hours in 70 DEG C under stirring, be then centrifuged for, wash, be dried；
（2）By step（1）Gained sample is added in 20ml dimethyl sulphoxide solutions with 2g Polyethylene Glycol, in 50 DEG C and blanket of nitrogen
Lower reaction 72 hours is enclosed, is then centrifuged for, washed, being dried；
（3）By 2.7g polyethylene glycol oxides and 0.3g polyvinyl alcohol mix homogeneously in aqueous, mechanical agitation 6 is little at 40 DEG C
When；
（4）By step（2）Gained 0.15g samples are added to step（3）Mixed liquor in, stirring 4 hours after, add 0.3g high
Lithium chlorate, continues to stir 5 hours at room temperature, then pours mixed liquor in Teflon mould into, is dried in fume hood
12 hours, place in vacuum drying oven and be dried 24 hours.
Embodiment two：
0.3g graphene oxides are added to into 40mlN, in dinethylformamide, ultrasonic disperse 30 minutes is formed dispersed
Graphene oxide mixed solution, measure 10ml thionyl chlorides and be added in obtained graphene oxide mixed solution, machinery is stirred
Mix down and reacted 24 hours in 70 DEG C, be then centrifuged for, wash, be dried；
（2）By step（1）Gained sample is added in 20ml dimethyl sulphoxide solutions with 6g Polyethylene Glycol, in 50 DEG C and blanket of nitrogen
Lower reaction 72 hours is enclosed, is then centrifuged for, washed, being dried；
（3）By 2.4g polyethylene glycol oxides and 0.6g polyvinyl alcohol mix homogeneously in aqueous, mechanical agitation 6 is little at 40 DEG C
When；
（4）By step（2）Gained 0.3g samples are added to step（3）Mixed liquor in, stirring 4 hours after, add 0.3g high
Lithium chlorate, continues to stir 5 hours at room temperature, then pours mixed liquor in Teflon mould into, is dried in fume hood
12 hours, place in vacuum drying oven and be dried 24 hours.
Embodiment three：
（0.2g graphene oxides are added to into 30mlN, in dinethylformamide, ultrasonic disperse 30 minutes is formed dispersed
Graphene oxide mixed solution, measure 10ml thionyl chlorides and be added in obtained graphene oxide mixed solution, machinery is stirred
Mix down and reacted 24 hours in 70 DEG C, be then centrifuged for, wash, be dried；
（2）By step（1）Gained sample is added in 20ml dimethyl sulphoxide solutions with 4g Polyethylene Glycol, in 50 DEG C and blanket of nitrogen
Lower reaction 72 hours is enclosed, is then centrifuged for, washed, being dried；
（3）By 2.1g polyethylene glycol oxides and 0.9g polyvinyl alcohol mix homogeneously in aqueous, mechanical agitation 6 is little at 40 DEG C
When；
（4）By step（2）Gained 0.45g samples are added to step（3）Mixed liquor in, stirring 4 hours after, add 0.45g
Lithium perchlorate, continues to stir 5 hours at room temperature, then pours mixed liquor in Teflon mould into, does in fume hood
Dry 12 hours, place in vacuum drying oven and be dried 24 hours.
Claims (5)
1. the preparation method of the solid polymer electrolyte of a kind of modified graphene oxide doping, it is characterised in that including following
Step:
（1）0.1~1g graphene oxides are added to into 50~100mlN, in dinethylformamide, 20~40 points of ultrasonic disperse
Clock, forms homodisperse graphene oxide mixed solution, measures 10~30ml thionyl chlorides and is added to obtained graphite oxide
In alkene mixed solution, react 12~36 hours in 50~80 DEG C under mechanical agitation, be then centrifuged for, wash, be dried；
（2）By step（1）Gained sample and Polyethylene Glycol are added in 10~20ml dimethyl sulphoxide solutions, at 50~70 DEG C and
React 48~72 hours under nitrogen atmosphere, be then centrifuged for, wash, being dried；
（3）Polyethylene glycol oxide and polyvinyl alcohol are mixed by certain mass ratio, mechanical agitation 4~6 hours at 40~60 DEG C；
（4）By step（2）Gained sample is added to step（3）Mixed liquor in, stirring 4~6 hours after, add corresponding lithium
Salt, continues to stir 5~8 hours at room temperature, then pours mixed liquor in Teflon mould into, and 12 are dried in fume hood
Hour, place in vacuum drying oven and be dried 24 hours.
2. the preparation method of the solid polymer electrolyte of a kind of modified graphene oxide doping as claimed in claim 1, its
It is characterized in that step（2）The Polyethylene Glycol consumption is 20~30 times of graphene oxide quality.
3. the preparation method of the solid polymer electrolyte of a kind of modified graphene oxide doping as claimed in claim 1, its
It is characterized in that step（3）The polyethylene glycol oxide is 9~7 with the mass ratio of polyvinyl alcohol:1~3.
4. the preparation method of the solid polymer electrolyte of a kind of modified graphene oxide doping as claimed in claim 1, its
It is characterized in that step（4）Described lithium salts is at least in lithium perchlorate, double trifluoromethanesulfonimide lithiums, dioxalic acid lithium borate
Kind, the consumption of wherein lithium salts accounts for the 5%~20% of polyethylene glycol oxide and polyvinyl alcohol quality.
5. the preparation method of the solid polymer electrolyte of a kind of modified graphene oxide doping as claimed in claim 1, its
It is characterized in that step（4）Described sample quality accounts for the 5%~15% of polyethylene glycol oxide and polyvinyl alcohol quality.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610626282.5A CN106684443A (en) | 2016-08-03 | 2016-08-03 | Preparation method for modified graphene oxide-doped solid polymer electrolyte |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610626282.5A CN106684443A (en) | 2016-08-03 | 2016-08-03 | Preparation method for modified graphene oxide-doped solid polymer electrolyte |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106684443A true CN106684443A (en) | 2017-05-17 |
Family
ID=58840041
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610626282.5A Pending CN106684443A (en) | 2016-08-03 | 2016-08-03 | Preparation method for modified graphene oxide-doped solid polymer electrolyte |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106684443A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107240720A (en) * | 2017-06-27 | 2017-10-10 | 齐鲁工业大学 | A kind of preparation method of modified carbon nano-tube doping solid polymer electrolyte |
| CN109569682A (en) * | 2017-09-29 | 2019-04-05 | 国家电网公司 | A kind of SPE electrolytic cell carries the preparation method of Ir-Ru catalyst with nitrogen-doped graphene |
| CN110190328A (en) * | 2019-05-24 | 2019-08-30 | 力信（江苏）能源科技有限责任公司 | Solid electrolyte material, dielectric film and preparation method thereof |
| CN112259832A (en) * | 2020-09-24 | 2021-01-22 | 江苏理工学院 | Preparation method and application of graphene-modified all-solid-state electrolysis |
| CN113078352A (en) * | 2021-03-26 | 2021-07-06 | 无锡纤发新材料科技有限公司 | Solvent and porous carbon reinforced composite polymer electrolyte and method thereof |
| CN113172069A (en) * | 2021-04-06 | 2021-07-27 | 杭州楠大环保科技有限公司 | Kitchen waste treatment method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102881940A (en) * | 2012-10-12 | 2013-01-16 | 西北工业大学 | Functional graphene oxide modified composite gel electrolyte and preparation method thereof |
| CN102891335A (en) * | 2012-10-11 | 2013-01-23 | 同济大学 | Preparation method of full-solid-state nano composite polymer electrolyte |
| US20150311569A1 (en) * | 2014-04-17 | 2015-10-29 | Aiping Yu | Wearable Battery Charger |
| CN105375070A (en) * | 2011-08-23 | 2016-03-02 | 株式会社日本触媒 | Gel electrolyte and cell using same |
| CN105453307A (en) * | 2013-09-13 | 2016-03-30 | 株式会社Lg化学 | Cathode for lithium-air battery and manufacturing method therefor |
-
2016
- 2016-08-03 CN CN201610626282.5A patent/CN106684443A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105375070A (en) * | 2011-08-23 | 2016-03-02 | 株式会社日本触媒 | Gel electrolyte and cell using same |
| CN102891335A (en) * | 2012-10-11 | 2013-01-23 | 同济大学 | Preparation method of full-solid-state nano composite polymer electrolyte |
| CN102881940A (en) * | 2012-10-12 | 2013-01-16 | 西北工业大学 | Functional graphene oxide modified composite gel electrolyte and preparation method thereof |
| CN105453307A (en) * | 2013-09-13 | 2016-03-30 | 株式会社Lg化学 | Cathode for lithium-air battery and manufacturing method therefor |
| US20150311569A1 (en) * | 2014-04-17 | 2015-10-29 | Aiping Yu | Wearable Battery Charger |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107240720A (en) * | 2017-06-27 | 2017-10-10 | 齐鲁工业大学 | A kind of preparation method of modified carbon nano-tube doping solid polymer electrolyte |
| CN109569682A (en) * | 2017-09-29 | 2019-04-05 | 国家电网公司 | A kind of SPE electrolytic cell carries the preparation method of Ir-Ru catalyst with nitrogen-doped graphene |
| CN109569682B (en) * | 2017-09-29 | 2022-07-26 | 国家电网公司 | Preparation method of nitrogen-doped graphene-loaded Ir-Ru catalyst for SPE electrolytic cell |
| CN110190328A (en) * | 2019-05-24 | 2019-08-30 | 力信（江苏）能源科技有限责任公司 | Solid electrolyte material, dielectric film and preparation method thereof |
| CN112259832A (en) * | 2020-09-24 | 2021-01-22 | 江苏理工学院 | Preparation method and application of graphene-modified all-solid-state electrolysis |
| CN113078352A (en) * | 2021-03-26 | 2021-07-06 | 无锡纤发新材料科技有限公司 | Solvent and porous carbon reinforced composite polymer electrolyte and method thereof |
| CN113078352B (en) * | 2021-03-26 | 2022-04-01 | 无锡纤发新材料科技有限公司 | Solvent and porous carbon reinforced composite polymer electrolyte and method thereof |
| CN113172069A (en) * | 2021-04-06 | 2021-07-27 | 杭州楠大环保科技有限公司 | Kitchen waste treatment method |
| CN113172069B (en) * | 2021-04-06 | 2021-12-14 | 杭州楠大环保科技有限公司 | Kitchen waste treatment method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Xiang et al. | A flame-retardant polymer electrolyte for high performance lithium metal batteries with an expanded operation temperature | |
| CN106684443A (en) | Preparation method for modified graphene oxide-doped solid polymer electrolyte | |
| KR101889118B1 (en) | Lithium ion secondary battery | |
| Deng et al. | Gel polymer electrolyte with high performances based on biodegradable polymer polyvinyl alcohol composite lignocellulose | |
| CN102005611A (en) | Polymer electrolyte and preparation method and application thereof | |
| CN111900469B (en) | Flexible solid film and flexible solid electrolyte film based on chemical cross-linked metal-organic framework material and preparation method thereof | |
| CN111786018B (en) | High-voltage polymer electrolyte, high-voltage polymer lithium metal battery and preparation method of battery | |
| WO2016029379A1 (en) | Fluorine-substituted propylene carbonate-based electrolyte and lithium-ion battery | |
| CN108306046A (en) | A kind of all-solid-state composite polymer electrolyte and preparation method thereof | |
| CN104466139A (en) | Preparation method of polyaniline-clad germanium-doped lithium manganate composite cathode material | |
| CN104409770B (en) | Preparation method of polymer electrolyte containing allyl functionalized ionic liquid | |
| CN104241572A (en) | Preparation method for alkaline solid polymer electrolyte fiber membrane, membrane and battery | |
| CN110224173A (en) | A kind of lithium battery solid polymer electrolyte capable of self-healing and preparation method thereof | |
| CN108172898B (en) | Composite electrolyte, preparation method thereof and all-solid-state sodium ion battery | |
| CN107180998B (en) | A kind of electrolyte and lithium ion battery | |
| CN111525187B (en) | Sulfonated polyvinyl alcohol solid polymer electrolyte membrane for lithium battery and preparation method thereof | |
| CN102055017A (en) | Carbonic ester electrolyte with annular sultone and oxalyl lithium tetraborate composition added | |
| CN105789702A (en) | Single-ion polymer electrolyte and preparation method thereof and lithium-ion secondary battery | |
| CN105244537B (en) | A kind of method that doping prepares composite polymer electrolyte film | |
| CN111320753B (en) | Polymer, polymer electrolyte membrane, nonaqueous electrolyte solution, and lithium ion battery | |
| CN113363575B (en) | Sulfonic polymer eutectic solid electrolyte and preparation method thereof | |
| CN113206292B (en) | Polymer-based composite solid electrolyte and preparation method and application thereof | |
| CN111326797B (en) | Liquid polymer electrolyte, polymer electrolyte membrane and lithium ion battery | |
| CN106129393A (en) | A kind of ZnMoO40.8H2o lithium ion battery negative material and preparation method thereof | |
| CN101359748B (en) | Lithium-ion secondary cell and manufacturing method therefor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20170517 |