Energy density Regarding energy density, it is an indicator that affects the endurance performance of new energy vehicles. In this parameter, the energy density of lithium iron phosphate battery cells is only about 110 Wh/kg, while ternary lithium battery cells are generally 200 Wh/kg. In other words, for batteries of the same weight, the energy density of ternary lithium batteries is 1.7 times that of lithium iron phosphate batteries, which can extend the life of batteries for energy vehicles. news. There is one thing about safe new energy vehicles that has car owners talking, and that is spontaneous combustion. There are many spontaneous combustion accidents in new energy vehicles every year. Ultimately, this is about battery stability. In this regard, lithium iron phosphate batteriescurrently have the most thermally stable power batteries and have absolute advantages over ternary lithium batteries in terms of safety. The electrical heating peak of lithium iron phosphate batteries reaches 350°C, and the chemical components inside the battery need to reach 500~600°C before starting to decompose. However, the thermal stability of ternary lithium batteries is very average and will start to decompose around 300°C. Efficiency by temperature difference Of course, although lithium iron phosphate batteries are resistant to high temperatures, ternary lithium batteries have better resistance to low temperatures. This is the main technical route for manufacturing low-temperature lithium batteries. At minus 20°C, ternary lithium batteries can release 70.14% of their capacity, while lithium iron phosphate batteries cannotrelease only 54.94% of their capacity. And because at low temperature, the discharge platform of ternary lithium batteries is much higher than the voltage platform of lithium iron phosphate batteries, the startup is faster. Charging efficiency: On the one hand, ternary lithium batteries are more efficient. Lithium batteries are charged using the current limiting and voltage limiting method, which is the first stage of constant current charging. At this point, the current is large and the efficiency is high. After the constant current reaches a certain voltage, it enters the second stage of constant voltage charging. At present, the current is small and the efficiency is low. Therefore, the charging efficiency of both is measured by the ratio of constant current charging capacity to the total capacity of the battery, called constant current ratio. The results experimentals show that there is little difference between the two when charging below 10°C, but the distance will increase when charging above 10°C. When charging at 20°C, the constant current ratio of the ternary lithium battery is 52.75%. and the constant current ratio of lithium iron phosphate battery is 10.08%, the former is 5 times that of the latter. Lifespan The lifespan of lithium iron phosphate batteries is better than that of ternary lithium batteries. The theoretical life of a ternary lithium battery is 2,000 cycles, but when it reaches 1,000 cycles, the capacity drops to 60%. Even Tesla, the best in the industry, can only retain 70% of its capacity after 3,000 cycles, while lithium iron phosphate batteries can still retain 80% of their capacity after the same cycle. Written at the end In comparison, lithium iron phosphate batteries are safe, have a long lifelong life and resistant to high temperatures; Ternary lithium batteries have the advantages of light weight, high charging efficiency and low temperature resistance. Therefore, the different adaptability of the two is the reason why the two males coexist.
74v240ah lithium battery multiplex
The energy density of lithium batteries currently used in electric vehicles by Pacific Automotive Network is approximately 100-150Wh/kg, is 2 times higher than that of lead-acid batteries is about 3 times higher, and the cycleability is much higher than that of lead-acid batteries, so lithium-ion batteries are currently the preferred battery for the development of electric vehicles.
Energy density refers to the energy released by the battery per unit of mass or per unit of volume. energy, that is, the specific energy of thevolume or mass-specific energy. Both energy density and power density are changing quantities. After the battery is used several times, the energy density will decrease (the battery capacity will attenuate) and the power density will also decrease, and these two quantities will also change with changes in the environment. For example, they will change (usually decrease) to some extent during extremely cold or hot seasons.
Currently, no battery has the energy density necessary to be practical enough to drive an electric vehicle with a range of several hundred kilometers. Improving battery energy density is also a top priority in current battery research and development. Assuming that safety is solved, if the battery energy density can reach 300~400 Wh/kg, it will have the capacity to compete with it. Traditional fuel-powered locomotives in terms of cruising range, but another well-known problem with batteries is their lifespan. Battery energy density will decrease with battery usage, and this decay is not linear, but can be. a sudden decrease. Therefore, when developing automotive batteries, circularity is also a decisive factor.
(Photo/Text/Photo: Pacific Automotive Network Gu_)
72V40Ah, the energy is 72*40=2880Wh. The current energy density of lithium batteries can reach 200Wh/Kg, which is already very impressive. Let's calculate based on 200, the weight should not be less than 2880/200=14.4 kg. Basically, the weight is not less than 15 kg. This is a lithium-ion battery made of ternary materials. If it is made of lithium iron phosphate material, it will be veryvery powerful if it can reach 130 Wh/Kg. The lithium iron phosphate battery is: 2880/130 = 22 kg. This is only the case for battery cells. If it is a module and BMS, structural parts, etc. are added, the weight will increase.
As for the price. Let's calculate the ternary battery at the cheapest price of 1.2 yuan/Wh. The price is 2,880 x 1.2 = 3,500 yuan. If it is a lithium iron phosphate battery, the price is nearly 6,000 yuan based on the cheapest price of 2 yuan/Wh.
The calculations above are all relatively conservative and the values are relatively reliable.