Lithium ion batteries are a type of rechargeable battery that primarily relies on the movement of lithium ions between the positive and negative electrodes for operation. Lithium ion batteries use an embedded lithium compound as the electrode material. The common cathode materials for lithium-ion batteries currently include lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), lithium nickel oxide (LiNiO2), and lithium iron phosphate (LiFePO4).

Most rechargeable batteries for portable electronic devices are lithium-ion batteries, which have advantages such as high energy density, high output power, low self discharge, no memory effect, and wide operating temperature range. In addition to being applied in the field of consumer electronics, lithium-ion batteries with increasingly advanced performance can also be applied in the larger market economy scale energy storage and power battery (which instantly requires a large current) market, covering pure electric vehicles, hybrid vehicles, solar cells, large energy storage batteries, electric hand tools, electric motorcycles, electric bicycles, aerospace equipment and aircraft batteries, and other fields. For example, efficient new batteries such as lithium iron phosphate batteries have broken through various shortcomings of existing lithium and lead-acid batteries and are becoming a common alternative to lead-acid batteries - historically used in golf carts and multi-purpose vehicles.

Lithium ion batteries also have their own shortcomings, such as not withstanding over discharge, which can accelerate and shorten their lifespan. Using extremely low battery levels can damage the battery's durability, and it is also important to avoid long-term storage when the battery is out of charge; Not tolerant of overcharging. When overcharging occurs, it can irreversibly damage the battery's performance and is more likely to cause overheating and explosion due to the difficulty of charged ions flowing and energy accumulation; Aging is afraid of heat, and unlike other rechargeable batteries, lithium-ion batteries will inevitably slowly decline during use cycles, even if not in use, their capacity will decrease. Due to the fact that incorrect use can reduce lifespan and even lead to explosions, lithium-ion batteries are generally designed with multiple protection mechanisms to ensure safe use. Lithium ion batteries are prone to expansion, overcharging, overheating, immersion, use of non original chargers, or improper storage or use can all lead to expansion or even explosion.

So from a safety perspective, each airline has specific regulations for passengers to carry lithium batteries. Civil Aviation of China requires that personal consumer electronic products, such as watches, computers, cameras, mobile phones, laptops, portable cameras, etc., which contain lithium or lithium-ion battery cells or batteries, are allowed to board the plane; Each person should carry no more than 2 backup batteries, which can only be placed in hand luggage and must be stored separately. Short circuit protection must be taken, and the total lithium content of the same quality must not exceed 25 grams. It is prohibited to carry lithium-ion batteries in checked luggage. Before traveling, it is necessary to carefully read the "Notice on the Regulations on Carrying Lithium Batteries in Civil Aviation Passengers' Luggage".