| With the gradual development of the times,people’s over-exploitation of non-renewable resources has brought unpredictable crisis to the future of nature and human beings.The development and utilization of new energy is imminent,and the research of energy storage technology and device has become the core issue.What’s more,how to develop energy storage device with fast charging,long cycle-life and high energy density is the primary problem.Supercapacitor（SC）with high stability,low cost,high safety and environmental protection has become one of the most potential green energy storage devices.However,the limited capacity makes it need to be recharged repeatedly in use,which limits its practical application.Triboelectric nanogenerator（TENG）can be used as an energy harvesting device to assemble with SC for self-powered devices as its small size,simple technology and ability to collect various mechanical energy.This advanced integrated energy system can effectively collect sustainable energy in the surrounding environment and store it,which shows great application potential.In this paper,self-charging energy storage devices based on SC and TENG are studied,and their structure and materials are optimized to coordinate and improve performance of the device.The specific research contents are as follows:1.Nickel molybdate（NiMo O4）composite with high electrical conductivity was prepared by a simple and low-cost method.When assembled for asymmetric supercapacitor（ASC）,the device showed good electrochemical performance with the75%capacitance retention after 5000 cycles of charge and discharge.In addition,a single electrode TENG with micro-pores also exhibits good output performance,with the open circuit voltage,short circuit circuit and output power of 100 V,6μA and 450μW,respectively.The TENG as an energy harvesting device can collected energy from the human body,and the mechanical energy can be stored in the ASC through an external circuit to form a simple self-charging energy storage system.At the same time,the integrated energy system can be realized to power small electronic devices.2.The layered and compact Ni-Mn nanosheet array（NiMn-LDH@CC）on carbon cloth with good electrochemical performance was synthesized by hydrothermal method.Meanwhile,as a positive electrode to assemble with Fe2O3@CC,the ASC exhibited good specific capacitance and long cycle life.In addition,the TENG as the energy harvesting device,with silicone rubber as the friction layer and silver nanowires as the conductive layer presented the optimal output performance as follows:open circuit voltage between 250-300 V,short circuit current of about 3μA,output power of about1700μW,and the output performance remains stable after 2000 s working.The self-charging system assembled by the ASC and the TENG can collect the movement energy of the human body,convert it into electric energy and store in the SC,and power the LED lights.3.A CC based CoNi-LDH@CC//ACC asymmetric supercapacitor is designed,which has good flexibility and electrochemical performance.When the current density is 1 m A cm-2,the specific capacitance is 348 m F cm-2.At the same time,the energy density is still high(94.7μWh cm-2)when the power density is 700.4μW cm-2.In addition,the TENG made of CC and silicone rubber（CC-TENG）has excellent electrical performance and stability.Combining the two,an all-in-one portable self-charging system is designed to collect and store mechanical energy during human movement and power smart devices. |
