Research On Compressible Lithium-Ion Battery Based On Highly Elastic Three-Dimensional Graphene And Its Performance

In recent years,the development of wearable electronic equipment has gradually emerged,and energy storage devices that can match it are needed,and these devices can maintain stable energy storage performance under various deformations.However,the current research in this field mainly focuses on the flexible energy storage direction that can be bent or stretched,and the research on compressible/recovery energy storage devices is still very rare.Lithium ion battery?LIB?is an energy storage device with high voltage,small self-discharge,long cycle life and good safety performance.At present,the research on compressible LIB has gradually attracted people's attention.High elastic three-dimensional graphene has the prospect of being a compressible lithium ion battery electrode due to its excellent resilience,large specific surface area,porous structure and other characteristics.In this paper,highly elastic three-dimensional graphene is used as a skeleton,and positive electrode active material and negative electrode active material are loaded into it to obtain a composite electrode material,and further assembled into a quasi-all-solid lithium ion battery that can be compressed/recovered.The mechanical performance and energy storage performance during the recovery process are as follows:?1?First,the ice template method is used to prepare three-dimensional highly elastic graphene.Through immersion,hydrolysis and other processes,cobalt oxide,titanium dioxide and other active materials are obtained in three-dimensional graphene to obtain a compressible composite electrode.The microscopic morphology characterization shows active material particles It can be evenly dispersed inside the three-dimensional graphene.The compression recovery test shows that the recoverable compression deformation of the composite material reaches 90%,and it can maintain the resilience even if it is compressed more than 500 times.?2?Assemble the obtained compressible electrode material into a liquid electrolyte-based half-cell.The test results show that the quality of the three-dimensional graphene/cobalt oxide composite electrode material and the three-dimensional graphene/titania composite electrode material under uncompressed conditions The specific capacities can reach 445.5 and 242.5 m Ah g^-1,respectively.And under 90%compression deformation,the two electrode materials can still retain more than 90%mass specific capacity,which proves that the compressible electrode can still maintain the three-dimensional electron conduction network and ion transmission channel under large compression deformation.More importantly,the volume specific capacity and area specific capacity are increased by seven times and three times after compression,respectively.?3?Assemble the compressible electrode material into a quasi-all-solid battery using gel electrolyte.Energy storage performance tests show that this compressible quasi-all-solid battery can maintain capacity and rate stability under 60%compression deformation,and after 100 repeated compressions,its mass specific capacity loss is less than 5%.The research of this subject not only reveals the energy storage performance of the three-dimensional graphene electrode composite material based on high elasticity under compression/recovery deformation,but also provides new research ideas for the development of a new generation of compression-resistant LIB.