Preparation And Properties Of Self-healing Multifunctional Gel Polymer Electrolyte

In order to better solve the structural damage and injury problems encountered in the use of supercapacitors,this paper has prepare a series of gel polymer electrolytes（GPE）with self-healing properties,polyacrylic acid（PAAc）/isodecyl methacrylate（HA）/H₃PO₄ GPE,PAAc/HA/potassium ferricyanide（K₃[Fe（CN）₆]）/H₃PO₄ GPE and polyacrylamide（PAM）/k-carrageenan（KC）/Na₂SO₄ GPE.In addition,polyaniline（PANI）is used as electrode material to prepare flexible all-in-one supercapacitor,and studied the electrochemical performances of them.The specific contents are as follows:1.Physically cross-linked PAAc/HA/H₃PO₄ GPE is prepared by hydrophobic association method in system 1,with ionic conductivity of 0.09 S/cm and elongation at break of 114 mm/mm.The experimental results shows that the existence of hydrogen bonds in the hydrophobic association system make PAAc/HA/H₃PO₄ GPE exhibits good self-healing ability,and the self-healing efficiency reaches 92%（healing temperature of 70℃,healing time of 6 h）.In addition,the PAAc/HA/H₃PO₄/PANI flexible all-in-one supercapacitor prepared by in-situ polymerization of ANI shows a maximum specific capacitance of 195.7 m F/cm² at a current density of 0.2 m A/cm²（ANI concentration of 0.7 mol/L,deposition time of 15 min）.Due to the hydrogen bonding effect of GPE,the PAAc/HA/H₃PO₄/PANI flexible all-in-one supercapacitor is also self-healing with a high capacitance retention rate of 95%after 10cuts/healings,and can be used normally after bending at different angles,meeting the bending problems encountered in practical applications of the device.In addition,it shows good low temperature resistance with 85%capacitance retention rate at-20℃.2.K₃[Fe（CN）₆]is introduced to prepare PAAc/HA/K₃[Fe（CN）₆]/H₃PO₄ GPE on the basis of system 1.K₃[Fe（CN）₆]can not only be used as redox additive to make GPE exhibiting redox performance,and the Fe³⁺contained in it can also form ionic crosslinks with-COOH in AAc to improve the mechanical strength of GPE.The experimental results shows that the mechanical strength of the GPE is significantly improved under the multiple physical effects of hydrogen bonds and metal coordination from 0.5 MPa to 1.99 MPa,and it has a certain degree of self-healing and low-temperature resistance.The PAAc/HA/K₃[Fe（CN）₆]/H₃PO₄/PANI flexible all-in-one supercapacitor fabricated by in-situ polymerization of ANI exhibits excellent pseudocapacitance and excellent bending behavior,with a maximum specific capacitance of 390 m F/cm² at a current density of 0.5 m A/cm².The capacitance remain almost constant after 10 cuts/healings,and shows good energy storage capacity at-20℃.3.System 3 introduces KC into the PAM purely physical cross-linked network structure to prepare PAM/KC/Na₂SO₄ double-network GPE.The conductivity reaches0.0195 S/cm with the Na₂SO₄ concentration of 0.8 mol/L,and the mechanical strength increases from 0.1 MPa to 0.49 MPa with the increase of KC content,which effectively improves the mechanical properties of PAM/KC/Na₂SO₄ GPE.It also exhibits low-temperature resistance,and the existence of a large number of hydrogen bonds in the system also makes it self-healing.The PAM/KC/Na₂SO₄/PANI flexible supercapacitor is assembled using carbon cloth as the substrate by in-situ polymerization of ANI,which shows a maximum specific capacitance of 143.9 F/g（current density of 30 m A/g）.It has good deformation ability（capacitance retention rate is 77%after 100 bendings at 160°）.In addition,the supercapacitor also has self-healing properties（81%capacitance retention after 10 cuts/healings）and exhibits excellent low-temperature resistance with a 95%capacitance retention at-30℃.