Research And Application Of Zinc-Molybdenum Oxide Hybrid Supercapacitor

The production and construction of new capacitive energy storage devices that are environmentally friendly,pollution-free,high capacitance,long life,and low loss are of great significance to the modern information technology society.Traditional capacitive energy storage devices are mainly electric double layer capacitors and Faraday pseudocapacitors.However,each of them has its own shortcomings that limit its own better development,such as lower energy density.Therefore,they emerged on the basis of traditional capacitors.A more advanced energy storage device—hybrid supercapacitor（HSC）device,which is composed of Faraday pseudocapacitors and electric double layer capacitors,can have the advantages of both Faraday pseudocapacitors and electric double layer capacitors.extensive attention.Transition metal oxide HSC devices are a kind of HSC devices,which have become one of the hot research directions due to their environmental friendliness,low cost,and high performance.The performance of the electrode material itself is decisive for the performance of the transition metal oxide HSC device.Of course,the actual demand is that the performance of the HSC device can be higher and higher.Therefore,we need to invest more in electrode research.It is possible to make the performance meet our use requirements,and meet people’s present and future energy storage needs.The two work contents of this article are as follows:（1）The electrode material Zn₃Mo₂O₉ is synthesized from MoO₃ prepared in the ordinary hydrothermal environment in the laboratory.It has a unique nanosheet structure.The excellent performance of the capacitor is attributed to the unique structure of the nanosheet,and the large specific surface area.Fast electron transfer rate and comprehensive,deep characteristics.In addition,due to the presence of molybdenum oxide（MoO₃）,its conductivity can be improved.For the negative electrode,we use activated carbon（AC）purchased directly from Kuraray as the electrode material,and Zn₃Mo₂O₉ as the two poles of the HSC device respectively.The combined Zn₃Mo₂O₉//AC HSC device has a specific capacitance of 46 F·g^-1(current density of 1 A·g^-1),at this time the maximum energy density reaches 20.8 Wh·kg^-1 and the corresponding power density of 397 W·kg^-1.The specific capacitance retention rate after 1000cycles is 92.3%,which proves that the electrode material has good stability and provides a new thinking direction for capacitors.（2）On the basis of the first work,we optimized and innovated Zn₃Mo₂O₉.Using simple stirring reaction conditions,Zn₃Mo₂O₉ was carbon-coated.The synthesized composite material Zn₃Mo₂O₉@C was used as the cathode material.The carbon-coated Zn₃Mo₂O₉ had a structure It becomes looser,makes its conductivity more excellent,has carbon as a material"skeleton",provides a stronger and more stable material for the capacitor,thus improves the capacitor’s cycle stability performance,thereby achieving an improved hybrid super.The overall performance of the capacitor is assembled into a Zn₃Mo₂O₉@C//rGO HSC device with rGO（reduced graphene oxide）synthesized in the laboratory as the negative electrode.The test results show that:（1）at the same current density of 1 A·g^-1,the specific capacitance of the assembled HSC device is 134 F·g^-1,and the energy density of the complete capacitor reaches47.6 Wh·kg^-1,（2）At the same current density Under cycling conditions,after 1000 cycles,the retention rate of specific capacitance is higher,which is 96%.The performance of Zn₃Mo₂O₉@C//rGO HSC device studied in this paper is excellent.This work provides a new idea for Zn₃Mo₂O₉ material optimization.