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# Energy Density Analysis of Batteries Lithium

Apr 05 , 2022

## Ⅰ. What is the energy density of batteries lithium?

1. The magnitude of the energy held in a unit of a specific space or quantity of material is referred to as energy density. The average unit volume or mass of power released by electrical batteries is known as the energy density of batteries lithium. The energy density of batteries lithium may be separated into two dimensions: weight energy density and volume energy density.

2. The weight energy density of batteries lithium is equal to the result that the capacity of electrical batteries and discharge platform are multipied then divide the weight, where Wh/kg (watt hour per kilogram) is the fundamental unit.

3. The volume energy density of batteries lithium is equal to the result that the capacity of electrical batteries and discharge platform are multipied then devide the volume, where Wh/L (watt hour per litre) is the fundamental unit.

4. The higher energy density batteries lithium have, the more power per unit volume or weight they can store.

## Ⅱ. What is the energy density of a single cell in batteries lithium?

1. The term "energy density of electrical batteries" is used to refer to two distinct concepts: the energy density of a single cell and the energy density of the electrical batteries system.

2. The smallest unit of an electrical batteries system is the cell. M cells make up a module and N modules make up a electrical batteries pack, which is the fundamental structure of an automobile power electrical batteries.

3. As the name suggests, the single cell energy density is the energy density in a single cell level.

## Ⅲ. What is the energy density of the batteries lithium system?

1. The system energy density refers to the ratio of the electric quantity of the entire electrical batteries system to its weight or volume after the combination of single cells. Because the internal electrical batteries system, which includes a electrical batteries management system, thermal management system, high and low voltage circuit, and other components, accounts for a portion of the electrical batteries system's weight and internal space, the energy density of the electrical batteries system is lower than that of a single cell.

2. The electrical batteries system power is equal to the result that the electric quantity of the electrical batteries system divide the weight or volume of it.

## Ⅳ. What exactly limits the energy density of batteries lithium?

1. The major cause is the chemical system of electrical batteries.

2. Generally speaking, the four sections of batteries lithium are highly important: positive electrode, negative electrode, electrolyte, and diaphragm. The chemical reaction takes place between the positive and negative electrodes, which are analogous to the governor and conception vessels of the human body. This shows how important they are. The relevance of the location is obvious. We all know that electrical batteries packed with ternary lithium as the positive electrode have a higher energy density than that packed with lithium iron phosphate as the positive electrode. What is the reason of this?

3. Graphite is the most common material of negative electrode used in batteries lithium, with a theoretical capacity of 372mAh/g. The theoretical capacity of the positive electrode material (lithium iron phosphate) is around 160mAh/g, while the ternary material nickel cobalt manganese (NCM) is around 200mAh/g. According to the barrel theory, the water level is defined by the shortest portion of the barrel, while the lowest limit of the energy density of batteries lithium is dictated by the positive electrode material. Lithium iron phosphate has a voltage platform of 3.2V, whereas ternary has a voltage platform of 3.7V. When comparing the two, the energy density is significantly different: 16 percent.

4. Of course, in addition to the chemical system, other aspects of the batteries lithium manufacturing process, such as compaction density, foil thickness, and so on, have an impact on energy density. In general, the higher the compaction density is, the larger the capacity of electrical batteries in a restricted space. Therefore, the primary material's compaction density is also one of the reference indications of the electrical batteries energy density.