It was reported that in early August, the new energy automobile industry interviewed BYD Chairman Wang Chuanfu at the Hunan Shaoshan Sanji Engineering Work Conference, which caused important securities newspapers, websites and agents, professionals, and more than one hundred news in just one week. Home media reports and hundreds of articles have also attracted great attention from the capital market. Is the energy density really increasing? Is it lithium iron phosphate or lithium iron manganese phosphate? Will the material change? For this reason, the media interviewed Dr. Weifeng Fan, the technical director of Chengdu Xingneng New Materials Co., Ltd., Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences.

Lithium iron phosphate is not a special case

disclosed BYD’s new technology lithium iron manganese phosphate battery

Dr. Fan said that it is not lithium iron phosphate and other types of metal ions, compound phosphates, and fertilizers, ammonium dihydrogen phosphate, ammonium phosphate, etc.) are similar, but different solubility calculations, so someone It may be said that the use of lithium iron phosphate and phosphorus fertilizers, but in fact, the solubility of lithium iron phosphate is very poor and cannot release the effective phosphorus components in the soil.

Fan believes that phosphate groups belong to another type of polyanionic compounds (polyanionic anode materials), because phosphate groups have more oxygen ions and coordination spaces, and can often form a steric polymer structure with transition metal ions.

Polyanion is a big spectrum

disclosed BYD’s new technology lithium iron manganese phosphate battery

The doctor fan has no peak value, M represents the previous alternative iron, manganese, cobalt, nickel, copper, chromium, such as any metal element, M is a base metal, chemical structure, safe to use March and lithium ion channel as a lithium battery Anode material, but different capacity, voltage, and ratio of performance, different life…

Phosphoric acid, lithium iron manganese or lithium iron manganese, right?

Dr. Weifeng Fan believes that any form of title is not important. The key is the ratio of iron to manganese. At present, there is no clear consensus on the three similar materials (532, 111, 811, etc.). Under what circumstances is the ratio of iron to manganese the most important. Good? Due to its good stability and performance, the real application in the future may be more metal complex phosphates.

disclosed BYD’s new technology lithium iron manganese phosphate battery

disclosed BYD’s new technology lithium iron manganese phosphate battery

Is technical authenticity a fact?

The theoretical specific capacity of lithium iron phosphate is 170mAh/g, the discharge path is 3.4V, and the energy density of the material is 578Wh/kg. The theoretical specific capacity of lithium manganese phosphate is 171mAh/g, the discharge path is 4.1V, and the material energy density is 701Wh/kg, which is 21% higher than the former.

According to Dr. Fan Weifeng, in the Chinese battery network, the energy density of existing lithium iron phosphate batteries is 90Wh/kg-130wh/kg. According to the 21% improvement in material energy density, even pure lithium manganese phosphate, the energy density can only reach About 150Wh/kg, the energy density of using lithium manganese phosphate battery can only reach below 150Wh/kg. Taking lithium iron phosphate battery as an example, if the hypothetical best strategy (150Wh/kg) is compared with the current worst strategy (90Wh/kg), the maximum improvement can be estimated to be 67%, but obviously this assumption can only be a hypothesis .