Ternary lithium-ion batteries refer to lithium-ion batteries that use lithium nickel cobalt manganese oxide (Li-Lon(nicomn)o2) as the cathode material, as well as precursor products of ternary composite cathode materials. Nickel salts, cobalt salts, and manganese salts are used as raw materials, and the internal ratio of nickel, cobalt, and manganese can be adjusted according to actual needs.
Ternary lithium-ion batteries have high energy density and high voltage, resulting in greater capacity for the same weight of battery pack, allowing cars to travel further and go faster. However, their drawback is poor stability; internal short circuits or contact with water in the cathode material can cause fires. Therefore, typical 18650 batteries are protected by a steel casing. Because Tesla's battery pack consists of approximately 7,000,000 18650 batteries, even with comprehensive protection, the risk of fire still exists in extreme collisions.
The reason is that when these two materials reach a certain temperature, ternary lithium analyzes at a lower temperature of around 200 degrees Celsius, while lithium iron phosphate analyzes at around 800 degrees Celsius. Furthermore, the chemical reaction of ternary lithium is more intense, releasing oxygen molecules and rapidly burning the electrolyte at high temperatures, triggering a chain reaction. Simply put, ternary lithium is more prone to ignition than lithium iron phosphate. However, it must be pointed out that we are referring to the materials themselves, not the finished batteries.
Lithium iron phosphate batteries are more stable. Even with puncture or short circuit, the battery pack will not explode or burn. It will not ignite when heated to 350°C (ternary lithium-ion batteries cannot remain undisturbed at 180-250°C). Therefore, in terms of safety performance, lithium iron phosphate batteries have a slight advantage.
Due to the potential safety hazards of ternary lithium materials, manufacturers are working hard to prevent accidents. Based on the pyrolysis characteristics of ternary lithium materials, manufacturers are investing heavily in overcharge protection, over-discharge protection, over-temperature protection, and overcurrent protection. Tesla has a battery management system that better manages its highly reactive ternary lithium-ion batteries, demonstrating its confidence in safety. Of course, with the continuous research and development in the battery field by battery companies, car companies, and professional battery management companies, more companies will be able to achieve excellent battery management, greatly improving safety.
Ternary refers to the name of the cathode material in lithium-ion batteries. Ternary materials are nickel-cobalt-manganese oxide (NiCONO) – the precursor products of ternary composite cathode materials are mainly nickel salts, cobalt salts, and manganese salts. The nickel, cobalt, and manganese content can be adjusted according to actual needs. 18650 refers to the external dimensions of a cylindrical battery: 18 refers to the battery diameter of 18.0 mm, and 650 refers to the battery height of 65.0 mm. These are commonly used in mobile phones. Lithium-ion batteries are quite common, and most batteries on the market are not specifically categorized here.
Ternary refers to the name of the positive electrode material in lithium-ion batteries. The traditional positive electrode material is lithium cobalt oxide (CoO₂). Ternary materials, namely lithium nickel cobalt manganese oxide (NiCoMn)O₂, are precursors to ternary composite positive electrode materials made from nickel, cobalt, and manganese salts. The ratio of nickel, cobalt, and manganese in the battery can be adjusted according to actual needs. Batteries using ternary materials as the positive electrode are safer than lithium cobalt oxide batteries, but their capacity is too low. When used in a mobile phone (the cutoff voltage of a mobile phone is generally around 3.4V), there will be a noticeable feeling of insufficient capacity. 18650 refers to the external dimensions of a cylindrical battery: 18 refers to the battery diameter of 18.0mm, and 650 refers to the battery height of 65.0mm. Other positive electrode materials besides ternary, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and NCA, etc., are also mentioned.
Lithium-ion batteries refer to a wide range of lithium materials. However, based on scientific terminology, the lithium-ion batteries we usually refer to should be called lithium-ion batteries/lithium secondary batteries and their corresponding negative electrode materials.
Energy density is a core element. Energy density refers to the energy stored in a given space or mass. The energy density of a battery is the energy released per unit volume or mass of the battery. Battery energy density = battery capacity * discharge plateau / battery thickness / battery width / battery length, with the basic unit being Wh/kg (watt-hours per kg). The higher the energy density of a battery, the more energy is stored per unit volume.
