Automotive-grade 21700 battery cells

What is a 21700 battery?

A 21700 battery is a high-capacity, rechargeable lithium-ion cell designed for superior energy efficiency and performance. With a standard size of 21mm in diameter and 70mm in length, these batteries were developed as a next-generation improvement over 18650 cells, offering increased power output, extended runtime, and higher energy density.

Why do electric vehicles use 21700 cells?

For instance, electric vehicles can use 21700 cells to store more energy in less space, resulting in longer driving ranges without increasing the size of the battery pack. A 21700 cell refers to an individual battery unit, while a 21700 pack is a configuration of multiple cells connected in series or parallel.

Are 21700 batteries based on lithium ion?

However, most 21700 cells are based on lithium-ion (Li-ion) technology, which is widely used across many types of rechargeable batteries due to its excellent energy density and long lifespan. There are several types of lithium-ion chemistries that could be used within the 21700 format:

Are 21700 batteries safe?

Unprotected 21700 batteries: Lack built-in safety features and are generally used in battery packs with external battery management systems (BMS). 21700 batteries are widely used in: Electric vehicles, with companies like Tesla and other manufacturers using them in battery packs for improved energy storage and performance.