All-solid-state battery and preparation method thereof

Abstract

The invention discloses an all-solid-state battery and a preparation method thereof. The all-solid-state battery comprises a positive pole piece, a solid electrolyte layer and a negative pole piece. The positive pole piece comprises a positive pole material layer and a quantum carbon-based film / metal composite interface layer, an active material of the positive pole material layer is a silver-doped graphene material, the solid electrolyte layer comprises a solid electrolyte, and the solid electrolyte is a perovskite type (ABO3) oxide solid electrolyte. The negative pole piece comprises a negative pole material layer and a quantum carbon-based film / metal composite interface layer, and an active material of the negative pole material layer is a lithium manganate material. By introducing thequantum carbon-based film / metal composite interface layer, the core problems of lithium dendritic crystal growth, low coulombic effect and interface side reaction in mass production of the three solid-state batteries are effectively solved.

Description

technical field [0001] The invention relates to a perovskite-type solid electrolyte battery and a preparation method thereof, belonging to the technical field of solid-state batteries. Background technique [0002] All-solid-state lithium-ion battery is one of the lithium-ion battery systems proposed to solve the problem of poor safety performance of liquid electrolyte lithium-ion batteries. It uses solid electrolyte materials with higher thermal stability to replace diaphragms and organic electrolyte solutions, fundamentally Improve the safety of lithium-ion batteries. Solid electrolyte, also known as superionic conductor, is a new type of electrolyte material that exhibits ionic conductivity in the solid state. It can not only overcome the shortcomings of internal short circuit and leakage of the battery, but also completely solve the problem of battery safety caused by flammable organic electrolytes. The problem is that the simplification of the safety device is realized...

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Problems solved by technology

[0004] However, there is an important problem in inorganic solid electrolytes, that is, the growth of lithium dendrites. It was first believed that the strength of inorganic solid electrolytes is high, and lithium dendrites cannot pierce them, so there is no problem with lithium dendrites. However, studies have shown that through LLZO electrolyte ion channels The position of the lithium ions when they reach the negative electrode is uneven, and there is also a gap between the solid electrolyte and the negative electrode interface, so it is easy to cause irregular deposition of lithium ions, thereby forming lithium dendrites, and once lithium dendrites appear, it means that the inside of the battery At the same time, the lithium dendrites will continue to absorb free lithium ions to grow, and eventually may puncture the separator, resulting in direct contact between the positive and negative electrodes of the battery and causing a short circuit.

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