LATP composite positive plate with low interface internal resistance, preparation method and all-solid-state lithium ion battery

Abstract

The invention relates to the technical field of solid-state lithium ion batteries, and discloses an LATP composite positive plate with low interface internal resistance, a preparation method and an all-solid-state lithium ion battery. Firstly, the LATP composite solid electrolyte is prepared through a co-sintering method, the sintering temperature is reduced, and the sintering time is shortened; then, the surface of the composite solid electrolyte is uniformly coated with an organic polymer electrolyte polyethylene oxide (PEO), so that on one hand, the solid-solid interface stress is buffered, the interface impedance is reduced, the lithium ion transmission capability is improved, meanwhile, the LATP is protected from being influenced by a metal lithium negative electrode, and the performance of the solid lithium battery can be greatly improved; comprise discharge capacity, rate discharge and cycle life.

Description

technical field [0001] The invention relates to the technical field of solid-state lithium ion batteries, in particular to a LATP composite positive electrode sheet with low interface internal resistance, a preparation method and an all-solid-state lithium ion battery. Background technique [0002] All-solid-state lithium batteries (ASLBs) are considered as one of the most promising alternatives for next-generation batteries, and their electrochemical performance is largely determined by the performance of solid electrolytes, which are mainly divided into two categories: polymer solid electrolytes and inorganic solid electrolytes. solid electrolyte. Inorganic ceramic solid electrolytes have high mechanical strength, can prevent the formation and growth of lithium dendrites, and have high temperature stability, which has become a hot research topic recently. However, the large-scale application of LATP still faces two technical difficulties: one is the poor point contact bet...

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Problems solved by technology

The patent with the application number CN202011050438.2 discloses the positive electrode sheet of the all-solid lithium battery and its preparation method and the all-solid lithium battery. By coating the positive electrode current collector with a functional coating containing polyionic liquid, the resistance of the solid interface layer is reduced. , to improve the capacity and rate performance of solid lithium batteries, but even the use of a small amount of ionic liquids will still have a negative impact on the safety of solid lithium batteries, which has potential safety hazards; the patent application number CN201910449510.X discloses a composite solid state Electrolyte and its preparation method, solid-state lithium battery, through the compounding of organic polymer and inorganic solid electrolyte layer, the pores on the surface of the inorganic solid electrolyte are filled, and the defects on the surface of the inorganic solid electrolyte layer are compensated, thereby effectively inhibiting the formation of lithium dendrites Growth, to avoid internal short circuit of the battery, but without optimizing the solid electrolyte / negative plate interface, there may be irreversible decomposition of the inorganic solid electrolyte, affecting the electrochemical performance and cycle life of the solid lithium battery, which has certain technical limitations

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