The general structure of lithium batteries is: cell module battery pack. Cell technology is the cornerstone of battery systems, and the process of assembling lithium battery cells into groups is called PACK, which can be a single battery or a series parallel battery module.
The difference between lithium battery cells, battery modules, and battery packs
In the field of batteries, sometimes we just talk about batteries, sometimes we talk about battery cells, sometimes we talk about modules, sometimes we talk about battery packs. Many customers are curious, what are the differences between these three? The fact is, batteries are a collective term, while cells, modules, and battery packs are different stages of battery application.
In the battery pack, in order to safely and effectively manage hundreds or thousands of individual cells, the cells are not randomly placed inside the casing of the power battery, but are arranged in an orderly manner according to modules and packages. The smallest unit is the battery cell, a set of cells can form a module, and several modules can form a lithium battery pack.
01. Cell: A cell refers to a single electrochemical cell that contains both positive and negative electrodes and is generally not used directly. In addition, the lifespan of battery cells is also the most critical factor, and any damage to a single cell can lead to damage to the entire battery pack.
02. Module: A battery module can be understood as an intermediate product between lithium-ion cells and packs formed by combining them in series and parallel, and installing a single battery monitoring and management device. Its structure must provide support, fixation, and protection for the battery cell, which can be summarized into three major items: mechanical strength, electrical performance, thermal performance, and fault handling ability.
03. Battery pack: Pack refers to the customized packaging, packaging, and assembly of lithium batteries, which are mainly divided into three main processes: processing, assembly, and packaging. When several modules are jointly controlled or managed by the BMS and thermal management system, this unified whole is called a lithium battery pack.
A single battery cell cannot be used. Only by combining multiple battery cells together, along with a protective circuit and casing, can it be directly used. This is the so-called battery module. A battery module is composed of numerous battery cells. Strict screening is required to assemble consistent battery cells into modular battery modules according to precise design, and install individual battery monitoring and management devices.
"Cell Module Battery Pack" is a sorting process from micro to macro level. The cells must be exquisite, and the module composed of the cells is safe, and the battery pack composed of the modules is also safe;
"Battery pack module cell" is a macro to micro ranking, where if the battery pack casing is damaged, the module casing can still be protected; The module casing is also damaged, and the battery cell body still has self-protection capability.
The production process from a simple battery cell to a battery pack is also quite complex, requiring multiple processes, which is no simpler than the manufacturing process of battery cells. Many friends who have not been exposed to lithium batteries generally regard the battery pack produced by the lithium battery manufacturer as a large battery. In fact, the lithium batteries we use are also the same as lead-acid batteries, which are obtained by parallel and/or series connection of individual batteries.