Lithium ion secondary accumulator battery and manufacturing process thereof

Abstract

The invention relates to a lithium electron power battery and a preparation process thereof. The lithium electron power battery comprises anode and cathode materials, positive and negative plates, an electrolyte and a diaphragm, wherein the positive and negative plates consist of positive and negative current collectors and active materials coated on the positive and negative current collectors. The anode material is prepared by mixing LiMPO4 and Li(Fe1-yMy)PO4 and preserving the heat for 15 to 30 hours at the temperature of between 500 and 900 DEG C, wherein M in the LiMPO4 is Co, Ni or Fe; M in the Li(Fe1-yMy)PO4 is one or two of Si, Nd, Al, La, Pr, Mg and the like; x is more than or equal to 0.001; and y is less than or equal to 0.02. The cathode material is mainly made of graphite with the carbon content of 99.99 percent and adopts a diaphragm material with good chemical stability. The positive and negative plates are put into the center of the folio diaphragm and lithium hexafluorophosphate / vinyl carbonic ether is poured into the diaphragm. A forming current is controlled in the range of 0.5 to 5C. The prepared battery has the characteristics of high electrical property, energy saving and environment protection.

Description

technical field

[0001] The present invention relates to an energy and new material technology, in particular to a lithium-ion secondary battery and its manufacturing technology technical background

[0002] LiCoO is a commonly used cathode material for lithium-ion batteries 2 It is a layered structure of cobalt lithium oxide, and the structure is relatively stable. In an ideal layered structure, Li 1+ and Co 3+ each in alternating octahedral positions in a cubic close-packed oxygen layer, in LiCoO 2 In general, there is a small amount of disordered structure, such as the rotation of O-Co-O sheets. In the charged state, aging can also change the surface of the particles and the corresponding electronic chemical properties. Spinel will also be formed when overcharged. Phase, such as charging to 4.7V, will lead to an increase in irreversible capacity and polarization, a slowdown of the kinetic process, and an increase in the number of dislocations and the number of internal ...