| With the rapid evolution of society and the continuous advancement of the financial condition level,the existing energy storage systems are increasingly unable to suffice the demand of human daily life.Lithium metal has received extensive attention due to its low density(0.53 g cm-3),low electrode potential（-3.04 V vs.SHE）and high theoretical storage capacity(3860 m Ah g-1),etc.Lithium metal batteries using lithium metal as anode play an important role in the development of energy storage systems.However,the safety problems brought by the increased energy density of lithium metal batteries have limited their commercial application.How to improve the energy density of lithium metal batteries while ensuring their safety performance is a crucial topic that needs to be settled urgently.In this paper,a series of ionogel electrolytes with high electrochemical performance and high safety performance were prepared by regulating the internal composition and structure of the electrolytes,and a series of systematic studies were carried out on their microscopic morphology,mechanical properties,thermal stability and electrochemical performance.The main work incorporates the following two sides:（1）A series of ionogel electrolytes were prepared by in-situ UV irradiation-initiated polymerization.The electrolytes use the chemically cross-linked network as a matrix to fix the liquid component and provide mechanical strength,and use solvate ionic liquid as liquid component to provide lithium ions and transport media.The prepared ionogel electrolytes possess excellent mechanical properties,excellent thermal stability and good electrochemical properties,and the electrolytes are adhesive,which can effectively improve the electrode-electrolyte interface contact problem.The lithium symmetric batteries assembled with the electrolytes can cycle stably for more than 3300 h at 25°C with current density of 1 m A cm-2,and the assembled lithium metal batteries exhibit excellent performance from 0 to 150°C.The high safety performance of lithium metal batteries is achieved while ensuring high electrochemical performance.（2）A series of composite ionogel electrolytes were prepared based on the nuclear pore membrane with vertical channels inside,and the polymer fillers were in-situ polymerized in the membrane by UV irradiation.The electrolytes use nuclear track membrane as the matrix,which is responsible for providing mechanical strength,and use ionogel electrolytes with excellent electrochemical performance as the filler,which is responsible for supplying lithium ions and transport medium.The composite ionogel electrolytes possess an ultra-high Young’s modulus,which can inhibit the growth of lithium dendrites,and at the same time,the electrolytes possess good thermal stability.Benefiting from its unique internal structure,the electrolytes exhibit superior ionic conductivity(>10-4S cm-1),superb lithium ion transference number（0.61）,and predominant anodizing potential（>5.3 V）.The lithium symmetric batteries assembled with the electrolytes can cycle stably for 700 h.Lithium metal batteries assembled with the electrolytes exhibit splendid cycle stability and high coulombic efficiency from room temperature to 90°C,and the lithium metal batteries also exhibit good rate performance.The important thing is that the thickness of the electrolytes is only 12μm,which can substantially enhance the energy density while achieving brilliant capability and marvelous safety performance of lithium metal batteries,which is of great value to the commercialization of lithium metal batteries. |
