Construction,Performance Regulation And Mechanism Of Cellulose Paper-Based Triboelectric Nanogenerators

At present,environmental pollution and energy crisis seriously restrict the sustainable development of human beings.The rapid development of the Internet of Things makes the sustainable power supply of hundreds of millions of mobile electronic devices a new challenge,which makes the development and utilization of new energy extremely urgent.As a new energy conversion device,triboelectric nanogenerator(TENG)can convert the mechanical energy of the environment into electrical energy,providing a new solution for the utilization of mechanical energy and sustainable power supply of electronic products.However,the environmental friendliness of triboelectric nanogenerators is limited because the main raw material source of current triboelectric nanogenerators is organic synthetic polymer materials.The use of environmentally friendly and renewable raw materials to prepare green electronic devices has become a research hotspot.Cellulose paper has the advantages of low price,good mechanical properties,environmental protection,renewable,and easy modification.Theoretically,it is an ideal raw material for the preparation of triboelectric nanogenerators.The development and utilization of cellulose paper-based triboelectric nanogenerators is not only conducive to promoting the greening of triboelectric nanogenerators,but also conducive to promoting the high-value utilization of cellulose resources.This paper focuses on the application of cellulose in triboelectric nanogenerator,aiming at the preparation of high-performance cellulose paper-based triboelectric nanogenerator,focusing on two aspects of material innovation and structural innovation.Using plant cellulose as raw material to prepare a variety of cellulose paper-based functional materials by using simple and low-cost ways.Based on them to build a series of cellulose paper-based triboelectric nanogenerators.This paper systematically studied the various factors affecting the output performance of these triboelectric nanogenerators,expounds its performance regulation mechanism and working principle,and explores its application in mechanical energy harvesting and self-powered sensors,thus providing a reference for extending the application of cellulose in triboelectric nanogenerator.The first part of the paper focuses on the research of material innovation(Chapter 2-4),mainly through the modification of cellulose to improve the performance of cellulose paperbased triboelectric nanogenerator or by replacing organic polymer material or metal material with cellulose material to improve the environmental friendliness of triboelectric nanogenerator.Cellulose/barium titanate composite paper(C/BT)and cellulose nitrate paper(NCP)were prepared from bamboo cellulose by wet papermaking combined with barium titanate dielectric regulation and nitrification modification.Cellulose conductive paper(CCP)was prepared from bamboo nanocellulose and go by vacuum extraction and filtration method.Ethylcellulose membrane(ECM)was prepared from ethylcellulose by a solutionregeneration method.A series of cellulose paper-based triboelectric nanogenerators were constructed by using the cellulose paper-based functional materials as positive friction layer(C/BT and ECM),negative friction layer(NCP),and electrode(CCP),respectively.After barium titanate dielectric regulation,the relative dielectric constant of C/BT composite paper was significantly improved,making it a highly efficient positive friction layer material.When barium titanate doping content was 4%,the open-circuit voltage and short-circuit current of triboelectric nanogenerator reached 118.5 V and 13.51 μA,which were increased by 51.3% and 41.2% compared with the control group,respectively.After nitration modification of cellulose,nitro was introduced,which endowed NCP with a stronger ability to obtain electrons and makes NCP became a highly efficient negative friction layer material.The output performance of the triboelectric nanogenerator was improved with the increase of cellulose nitrate content in NCP.The triboelectric nanogenerator prepared by NCP,ECM,and CCP was completely green.CCP had high conductivity and strong mechanical strength,and the output performance of the device as the electrode material was not different from that of Cu as the electrode material.In addition,the micro-morphology and thickness of the friction layer,the size,and frequency of the external force also had significant influences on the output performance of the triboelectric nanogenerators.The cellulose paper-based triboelectric nanogenerators have good output performance and working stability,and have good application prospects in mechanical energy collection and self-powered sensing.Based on the first part,the second part(Chapter 5 to Chapter 6)focuses on structural innovation,mainly through structural improvement to improve the performance of cellulose paper-based triboelectric nanogenerator or broaden its application scope.Nitrocellulose microporous membrane(NCM)was prepared by solution-regeneration film forming method using cotton cellulose as raw material and nitrocellulose microporous membrane(NCM)was used as friction layer to prepare single-electrode triboelectric nanogenerator(NS-TENG)and multi-unit integrated triboelectric nanogenerator(M-TENG)based on paper spring structure.A paper-based supercapacitor(P-SC)was prepared using CCP as electrode material and combined with M-TENG to form a self-powered power supply system(SCPS).The pore structure of NCM varied with the proportion of deionized water in the casting solution,which had a certain influence on the output performance of the triboelectric nanogenerator.When the proportion of deionized water was 3%,the output performance of NS-TENG was the best,and the open-circuit voltage and short-circuit current were 149.2 V and 13.73 μA,respectively.The single-electrode structure not only simplifies the preparation of triboelectric nanogenerators but also gives it the unique advantage of collecting energy from freely moving objects.The output performance of M-TENG can be controlled by changing the connection mode and the number of units.Electrochemical tests show that P-SC had good capacitance performance and a fast charge-discharge rate.SCPS can realize efficient collection,conversion,and storage of mechanical energy,and successfully drive a variety of small electronic devices,which has the potential as a sustainable power source.