In the 2016-2017 China Bus Industry Development Summit, Dr. Wang Shengwei, expert of fast charging technology of Ningde New Energy Technology Co., Ltd. (hereinafter referred to as "CATL"), with "CATL lithium iron phosphate fast charging technology of new energy bus application" As the theme, delivered a wonderful speech.
CATS was established in 2011, with strong reserves of technical resources and rapid development. In 2012, it won the support of the national 12th Five-Year Plan and established cooperation with foreign-funded luxury car company BMW. In 2013, CATL formed with Yutong, a well-known bus company in China. Cooperation; in 2014 the establishment of the German branch, 2015 academicians workstation set up, and selected national key research projects. Sales in 2015 ranked the world's top three, domestic first two, is expected to rank in this year is expected to further improve.
CATL is the only one with Japan and South Korea battery business on the subject of national enterprises, with international resources, international customers and international talent. Relying on strong human resources, R & D team is superior to R & D, from production design to production, to testing and verification, and has strong resource support, which has laid the three advantages of product safety, reliability and durability. In the field of fast-charge battery technology, CATL Houjibofa become the industry's shining star.
In the choice of fast charging materials, CATL to lithium iron phosphate as the main cathode material, graphite as the anode material. For many people think that lithium iron phosphate can not do fast charge, Wang Shengwei make a professional and detailed analysis. In his view, this understanding of some "only know one, I do not know the second" one-sidedness.
As we all know, the general chemical system of the battery, fast charge when the negative will produce by-products, thereby affecting the battery cycle and stability, can only be used to withstand the fast charge current of the anode material to fast charge. Fast charge from the field of professional terms, the focus of fast charge in the negative, and for the positive choice, whether it is selected ternary or lithium iron phosphate, will not affect the performance of fast charge to play, and its reliability . Therefore, the core technology of fast charge, through the chemical system and design optimization, to accelerate lithium-ion moving between positive and negative speed, reduce or block negative by-product generation.
But the lithium iron phosphate is not suitable for fast charge, there is a certain reference value, because the traditional lithium iron phosphate conductivity is relatively poor, affecting the fast charge of fever, so for the above two issues, CATL through in-depth technical research, Innovative solutions are given.
In the cathode, CATL developed the "super-electronic network" technology, making lithium iron phosphate has excellent electronic conductivity, up to 1000 times the ternary material, while lithium iron phosphate cathode also takes into account the high-speed rechargeable battery system Security and reliability.
In the negative graphite surface, CATL uses the "fast ion ring" technology modification, modified graphite both super fast charge and high energy density characteristics, fast charge negative side no longer appear by-products, so greatly improve the lithium ion in the graphite layer Embedded speed, with 4-5C fast charge capacity to achieve 10-15 minutes fast charge, and to ensure that the system level 70wh / kg above the energy density, to achieve 10,000 cycles of life.
In addition, CATL is currently developing the fast charge products, equipped with self-developed thermal management system, fully identify the fixed chemical system at different temperatures and SOC under the "healthy charging range", greatly broaden the operating temperature of lithium batteries. When the battery is in the cold northern winter, the water heating system for the core heating at low temperature until the cell temperature reaches the required, that is, open fast-charging mode; summer heat in the South, the battery system automatically heating alarm, water cooling system Batteries cooling, truly "full climate" fast charge.
Wang Shengwei said, CATL choose lithium iron phosphate - graphite fast charge technology has three characteristics. The first is the high rate, ten minutes quickly filled, basically comparable to the fuel truck fueling time; followed by long life, can reach more than 10,000 times the charge and discharge cycles to meet customer requirements for bus customers 8 years warranty; again high security System, lithium iron phosphate at this stage is more mature and safe power battery, in the "Eleventh Five-Year" demonstration application, in the "second five" development of electric vehicles as the main force. Lithium iron phosphate battery is a proven, more mature battery materials.
Fast charging technology for lithium iron phosphate market applications, Wang Shengwei CATL as early as three years ago has been studied, a lot of bus-like customer cars already in use, the reason now began to promote, mainly from the product responsible, CATL hope Has been developed to provide reliable, safe and can meet the use of the bus battery products.
Fast charging technology of lithium iron phosphate, coupled with the escort of thermal management system, CATL seems to have walk in the forefront of the industry, is a step by step to meet the bus long-term, reliable and safe fast charge demand, the future CATL fast charge technology prospects .