All-solid-state lithium-ion battery -Lithium - Ion Battery Equipment

All-solid-state lithium-ion battery -Lithium - Ion Battery Equipment

Lithium-ion batteries have been attracting attention since they were put into the market in 1991 because of their excellent functions such as high energy density and long life. It has become an integral part of the energy economy in the 21st century. However, there are still some urgent problems to be solved in the application of lithium-ion batteries in the field of large-scale batteries such as automobiles and energy storage, such as safety issues. The organic electrolyte of lithium-ion batteries is volatile, flammable and explosive, and is the primary element that causes the safety of lithium-ion batteries.All-solid-state lithium-ion batteries solve this problem from the root, and also have the advantages of large capacity and light weight. It is imminent to study all-solid-state lithium-ion batteries that can be industrialized.

1. Overview of all-solid-state lithium-ion batteries

An all-solid-state lithium battery is an energy storage device that does not contain liquid in its structure and all materials exist in a solid state compared to a liquid lithium battery. Specifically, it is composed of positive electrode material + negative electrode material and electrolyte, while liquid lithium battery is composed of positive electrode material + negative electrode material + electrolyte and separator.

Research progress of all-solid-state lithium-ion batteries

As the core component of all-solid-state lithium-ion batteries, lithium-ion solid electrolyte materials are the core materials to achieve their high performance and one of the bottlenecks affecting their practicality. The development history of solid electrolytes has been more than a hundred years, and there are hundreds of solid electrolyte materials studied, and solid electrolytes can only be used as long as the conductivity at room temperature or not too high temperature is greater than 10-3S/cm. Electrochemical power systems, and the conductivity value of most materials is several orders of magnitude lower than this value, which makes solid electrolyte materials with practical application value very few. (Lithium - Ion Battery Equipment)

2. Research progress of solid electrolytes

As a crucial part of the battery, the electrolyte function largely determines the power density, cycle stability, safety function, high and low temperature function and service life of the battery. The indicators for judging electrolytes generally include:

(1) Ionic conductivity: The ionic conductivity will affect the bulk resistance of the assembled battery. For solid electrolytes, the ionic conductivity is generally required to reach more than 10-4S/cm.

(2) Migration number: refers to the contribution of lithium ions in the current passing through the electrolyte. Ideally, the migration number is 1. If the migration number is too low, anions will be enriched on the surface of the electrode, resulting in increased battery polarization and increased resistance.

(3) Electrochemical window: The electrolyte needs to have high electrochemical stability within the working voltage range of the battery, otherwise it will decompose during the working process, and the electrochemical window is generally required to be higher than 4.3V.

The solid electrolytes currently being studied mainly include oxide solid electrolytes, sulfide solid electrolytes, polymer solid electrolytes, and composite solid electrolytes. The following will introduce these solid electrolytes and their research progress in detail.



Contact Us

24 hours online service