Design And Performance Study Of Flexible And Stretchable Lithium Ion Battery

In recent years,the development of flexible/stretchable electronics has gained momentum,and for these devices,power supply devices are essential for their proper operation.Lithium-ion batteries have the advantages of small size,high energy density,safety and mature technology,and are considered to be the ideal power unit for various flexible/stretchable electronic energy storage systems.To prepare essentially stretchable lithium-ion batteries,the core functional layers,including electrodes,electrolytes and packaging materials,need to be intrinsically stretchable,and the layers must be compatible with each other.Although some relevant studies have prepared the intrinsically stretchable electrode and electrolyte at the same time,there are still some problems such as complex electrode preparation process,poor electrode stretchability or complex electrolyte synthesis method,and the performance of stretchable batteries still needs to be further optimized.Specifically,we approach our work from the following perspectives:(1)We achieved the design of an all-component flexible stretchable lithium-ion battery by exploiting the inherent stretchability of silver nanowires(AgNWs)/active materials/PDMS composite electrode and a single network polymer electrolyte.The active material in contact with AgNWs is transferred to PDMS,and the in-situ thermal polymerization of the PDMS precursor imparts a strong physical interaction between the polymer and the AgNWs/active material,making the electrode inherently stretchable.Batteries based on stretchable electrodes and stretchable polymer electrolytes can be stable for more than 70 cycles,which is also far better than lithium-ion batteries using liquid electrolytes.(2)In order to further optimize the mechanical properties and ionic conductivity of the electrolyte,at the electrolyte level,we designed a solid electrolyte based on Mxene.Through thermal polymerization,the solid electrolyte exhibits 600%tensile property,and the ionic conductivity at room temperature can reach 7.3×10-4 S/cm.For example,lithium/polymer electrolyte/LFP(LTO)batteries can be cycled more than 40 times with an average coulomb effect of more than 95%.At the same time,lithium/polymer electrolyte/LFP batteries showed better cycling performance than batteries using liquid electrolytes.This part of the research provides a new idea for the design and synthesis of polymer electrolyte,the key functional layer of high-performance flexible stretchable lithium batteries.