In cylindrical cells, large cylindrical cells such as 2175 accounted for 80.5% and 14.3%, respectively, and the market share of 18650 decreased to 3.1%. In 2020, Prismatic, Pouch and cylindrical lithium battery cell accounted for 81.8%, 5.8% and 12.4%, respectively. Prismatic battery cell is a kind of power battery which is popularized earlier in China. With the market’s pursuit of energy density and the progress of production technology, aluminum shell has gradually become the mainstream.

The shell is usually steel or aluminum shell. Fuse is fused to cut off the current loop inside the battery. When overcharged, the pressure generated inside the battery causes the OSD to trigger an internal short circuit and generate a large instantaneous current. Normally it is usually a thin metal sheet and can be used together with fuse, which can be designed on the positive terminal fluid collector. OSD (Overcharge Safety Device), currently this Safety design can be seen on many batteries. When needling occurs, the local large current generated at the needling position rapidly reduces the current per unit area through the large copper sheet, which can prevent local overheating at the needling position and slow down the occurrence of battery thermal runaway. This is done by adding a metal layer, such as a copper sheet, to the outer part of the coil. Among them, two in the red circle are safety structures, NSD needling safety devices OSD overcharge protection device. Basic structure of Prismatic battery cellĪs shown in the above explosion diagram, the main components of a typical prismatic lithium battery include: top cover, shell, positive plate, negative plate, laminated or winding composed of diaphragm, insulation parts, safety components, etc.

Prismatic lithium ion batteries