Preparation And Study Of Large Area Electrochromic Glass

The increasing energy demand has become a severe challenge to the development of human society.It is urgent to improve energy efficiency and maintain sustainable economic development.According to statistics,building energy consumption in China mainly includes winter heating and summer refrigeration,which accounts for about 40 percent of the total energy consumption in the whole society,so building energy saving is of great significance.Electrochromic technology provides a new solution for the energy saving of modern buildings.It can adjust the visible light transmittance and solar radiation energy of glass according to human's will.Therefore,the industrialization of large-area electrochromic glass has also been put on the agenda.However,there is still a long way to go from a small area of electrochromic glass in the laboratory to a large area of electrochromic glass that can be used in real life.Many technical and technological problems need to be solved urgently.The cycle life and stability of electrochromic glass also need to be improved.In this paper,tungsten oxide and nickel oxide electrochromic films were prepared by various methods,and PMMA/PC and PVDF-HFP/DMF reference solid state electrolytes were synthesized,A large area of electrochromic glass was assembled by hot pressing film method,and the cycle stability of the device was tested.Furthermore,the complementary electrochromic glass with tungsten oxide/nickel oxide composite electrode is fabricated,which improves the light modulation range and response speed of the device,and makes the device have a good function of blocking sunlight and preventing peeping.Firstly,large area molybdenum doped tungsten oxide electrochromic films were prepared by magnetron sputtering,spraying,spray pyrolysis and screen printing,and PMMA/PC reference solid electrolyte was prepared.The electrolyte and electrochromic film were assembled by hot pressing film.The optical modulation range,response time and cycle stability of the device were measured.It is observed that with the increase of cycle times,bubbles will be produced gradually,and the modulation range and response time will decrease gradually.The changes of film and electrolyte composition are analyzed by electron energy spectrometer and infrared spectrometer,respectively.It was found that there was a strong interaction between Li+ and PC molecules in the electrolyte,resulting in the formation of [Li PC]+.It has lower lowest unoccupied molecular orbital than pure PC solvent.PC-Cl O4-compound oxidation results in the deprotonation of PC and the formation of HCl O4.The existence of anions reduces the oxidation stability of the solvent and changes the decomposition kinetics and thermodynamics,resulting in the formation of gas.The cycle stability of the device is reduced.In order to alleviate the bubble problem,the PVDF-HFP/DMF reference solid electrolyte was prepared,and the device was assembled by hot-pressing film method,and the performance of the device was tested.It is found that when 50% electrolyte of PVDF-HFP:DMF is assembled into the device without bubbles after 100 cycles,the decomposition of electrolyte in the device cycle is improved and the cycle life of the device is increased.Finally,in order to improve the range of light modulation,speed up the response time,make the chromotropic glass better to save energy consumption and prevent peeping,the complementary electrochromic glass with tungsten oxide/nickel oxide composite electrode was prepared.The influence of preparation parameters on the properties of nickel oxide thin films is discussed.When the RF sputtering Ni O target,the sputtering power is 60 W,the ratio of oxygen to argon is 0:70,and the sputtering bias voltage is 224 V,the discoloration performance of the device is the best.When the sputtering power is 60 W and the ratio of oxygen to argon is 30:60,the discoloration performance of the device is the best.Based on the above research,it is expected to provide good engineering support for large area electrochromic glass which can be used for a long time.