The high-energy tantalum hybrid capacitor niobium shell and the manufacturing method thereof, the high-energy tantalum hybrid capacitor shell comprises a niobium shell and a niobium insulator; The niobium shell is a straight cylindrical cap structure, and the niobium insulator is composed of niobium cap, glass body, tantalum wire, steel ring and metal tube. The niobium cap and tantalum wire are sealed together after melting glass through high temperature sintering, while the steel ring and metal tube are respectively made by mechanical compression with niobium cap or tantalum wire. At the same time, the method of processing the shell is also published, such as stamping, cutting, stamping forming of glass billet, crimping of steel ring, assembly and sintering, metal tube. The shell of high-energy tantalum hybrid capacitor manufactured by this technology has good sealing performance, which is convenient for welding electrode and external circuit, and meets the requirement of no leakage after packaging of high-energy tantalum hybrid capacitor.
The existing all-tantalum electrolytic capacitors are made of pure tantalum powder as anode and niobium shell as cathode material. Tantalum capacitors have the advantages of stable electrical performance, small volume and large capacitance among all capacitors. As communications, medical, transportation and other fields of electrical and electronic equipment to the small size, high power, high frequency, high voltage direction development, electronic equipment to the rated working voltage of capacitor, the high frequency characteristics and specific storage volume requirements to higher and higher, especially in aerospace equipment significantly improve capacitor energy density and payload capacity. Due to the increasing demand for tantalum electric container products, tantalum resources are in short supply. However, the current researches have failed to effectively solve the problem of completely substitutable materials, so this aspect has become one of the research topics of many scholars.
As rare elements of the same family, niobium and tantalum have similar electronic structures and physical and chemical properties. Moreover, niobium is more abundant than tantalum, and its price is low and stable, so it has become the first target of research. Niobium as a positive grade is damaged by heat and electrical stress, resulting in the increase of leakage current and affecting the use of capacitors. However, niobium as cathode will not affect the performance of tantalum capacitor, so niobium can completely replace tantalum in cathode material of capacitor (i.e. shell).
If niobium is used as the shell, the material has high melting point, good processing performance, corrosion resistance, low steam pressure, small expansion coefficient and other excellent properties; However, the hardening phenomenon of niobium plate is more serious in the process of deep drawing and stamping, and it is easy to produce cracking, tensile marks and deformation during deep drawing and extension of niobium shell, which will affect the product size, appearance and product consistency. The above characteristics and defects of niobium plate are more serious than those of the same family tantalum. Therefore, in the field of high energy capacitors, niobium is not used as cathode shell in the existing technology, but tantalum is generally considered.
