Font Size: a A A

Preparation Of Novel Poly-ionic Liquid Electrolyte And It's Performance In Lithium Ion Battery

Posted on:2019-03-04Degree:MasterType:Thesis
Country:ChinaCandidate:X Q ChenFull Text:PDF
GTID:2321330566458383Subject:Applied Chemistry
Abstract/Summary:PDF Full Text Request
As advantage of higher voltage,higher energy density,pollution–free and loger cycle life for Lithium-ion battery have attracted increasing public concern in areas of energy chemistry and material chemistry.Traditional Lithium-ion battery make up by cathode material,anode material,separator and electrolyte composition.Electrolyte as a part for Lithium-ion battery,when current is transmitted in positive and negative,not only conveying current,also affect the properties of battery such as reversible capacity,safety,cycle life and so on.The traditional electrolyte,which is organic,even though have higher ion conductivity,but also have a bad impact on safety of battery,that caused by the problem of flammable for electrolyte.Composited gel polymer electrolyter?CGPE?was developed in order to solve some problems found in problem of safe at lithium-ion battery.The same time,this work can present the prospects of CGPE frameworks expanded application range,and the details are summarized as follws:?1?A novel two-dimensional?2D?composite gel polymer electrolyte?CGPE?was synthesized by the co-assembly of ionic liquid crystals[1-hexadecyl-3-methyl tetrafluoroborate([C16mim]BF4)],polyethtlene glycol diacrylate?PEGDA?as crosslinking agent and poly cationic liquids[1-?hexyl methacrylate?-3-butyimidazolium tetrafluoroborate?PMOBIm6-BF4?]along with the imidazolium moieties through a flexible spacer.Ionic liquid crystals were used to induce 2D ion-conductive pathways in the polymer cationic ionic liquid,and polymer cationic ionic liquids acted as ion-conductive media for lithium-ion batteries.The assembly ability of ionic liquid crystals can not only develop lamella structure and ordered channel for efficient Li-ion transportation in CGPE,but also show efficient enhancement for ionic conductivity of poly ionic liquid.Owing to good thermal stability,non-inflammability,and high ionic conductivity,the PMPC0.5 electrolyte containing3/1/0.5(poly-MOBIm-BF4/PEGDA/[C16mim]BF4)exhibited an excellent lithium-storage performance within a high ionic conductivity of 7.14×10-5 S cm-1 at 25?and wide electrochemical window of up to 4.7 V vs.Li+/Li.The Li/PMPC0.5/LiFePO4 coin cells using the CGPE as electrolyte delivered a specific capacities of 136.7 mAh g-1 in the first cycle and 118.9mAh g-1 and coulomd efficiency of 99.74%in the 40th cycle at 0.1 C rate.?2?GCPE was synthesized composited ionic liquid of 1-ethly-3-methylimidazolium tetrafluoroborate?EIME-BF4?]as adition with interpenetrating network polymer matrix made up by poly cationic liquids[1-?hexyl methacrylate?-3-butyimidazolium tetrafluoroborate?PMOBIm6-BF4?]and PEGDA.Owing to good electrochemical performance and stability of electrolyte,the CGPE of M6PE-50,that containing 50 quality percentage of 0.1 mol kg-1 EIME-BF4/LiBF4 in quality rate of poly-MOBIm6-BF4/PEGMA was 3?1,exhibited an excellent lithium-storage performance within a high ionic conductivity of 1.32×10-3 S cm-1 at 25?and wide electrochemical window of up to3.86 V vs.Li+/Li.The Li/M6PE-50/LiFePO4 coin cells using the CGPE as electrolyte delivered a specific capacities of 139.0 mAh g-1 in the first cycle and 120.0 mAh g-1 and coulomd efficiency of89%in the 50th cycle at 0.1 C rate.?3?The CGPE based on N,N-diethyl-N-methyl-N-?2-methoxyethyl?ammonium tetrafuluoroborate?DEME-BF4?ionic liquid fillers,lithium-tetrafuluoroborate?LiBF4?and chitosan with anion of tetrafuluoroborate?HACC-BF4?.Also the result CGPE of HA-BF4 obtained a higher ionic conductivity up to 2.02×10-3 S cm-1 at the room temperature when 80 wt%LiBF4/DEME-BF4 of 0.1 mol kg-1 was contained,and the maximum lithium ions transference number of 0.54 was achieved.Electrochemical performance of the CGPE was evaluated in Li/HA-BF4-80/Li FePO4 coin cell.The Li/HA-BF4-80/LiFePO4 coin cells using the CGPE as electrolyte delivered a specific capacities of 152.0 mAh g-1 in the first cycle and 140.0 mAh g-1 and coulomd efficiency of 91%in the 100th cycle at 0.1 C rate.
Keywords/Search Tags:CGPE, Lithium-ion battery, polymer ionic liquild, chitosan, ionic liquild crystal
PDF Full Text Request
Related items