Dynamic safety of lithium-ion battery cathode materials and design influence

First post by: www.itsbattery.com

With IBM Laptop Battery technology continues to update and development of its light, high-capacity, long-life advantages gradually consumers of all ages. By phone market has expanded to cameras, model aircraft, toys, and other areas. In recent years, IBM ThinkPad T41 Battery electric power Hardware Tools tools, backup power Regulators regulators, electric bicycles, light electric vehicles and other large equipment on the Application of a growing concern, and the equipment requirements of a large-capacity battery , High-power conditions. IBM ThinkPad T42 Series Battery can meet the high-security, high power, long life's basic requirements, many experts and scholars on the important subject. Power lithium-ion batteries generally refers to security issues because of improper use of battery power, functional failure, accidents and abuse battery Guzhang leakage, temperature and pressure beyond the use of standard, or even the explosion and fire incidents, resulting in the user lives and property are threatened . One explosion and fire is the most serious safety incidents. Lithium-ion batteries abuse led to the fire explosion of internal reasons are very complicated, but most of them are caused by high temperature and pressure, and the causes of the two most can be summed up in the lithium-ion battery thermal runaway reaction, which is fever. These reactions are generally fever: the cell membrane electrode SEI decomposition, embedded lithium and the reaction solvent, the cathode material decomposition, and so on. Cathode material is the key advantage of the LiMn2O4 Lithium-ion battery power in the security issue, the electrode IBM ThinkPad T43 Battery in the cathode material is the key, but also trigger lithium-ion battery the main reason for potential safety problems. Seeking high energy density, high security, environmental protection, and the cheap power battery electrode material is the key to development. The current widespread use of the cathode material are LiCoO2, manganese lithium-acid, nickel and cobalt and manganese Lithium iron phosphate lithium. On the data obtained at home and abroad, LiCoO2 used to power batteries of greater security risks, not generally as the motive power battery cathode materials; LiMn2O4 the use of more common; nickel and cobalt LiMn2O4 domestic use less, China Taiwan and Japan that some manufacturers use. Because manganese is rich in resources (in particular China, the world's reserves of the third), low-cost, environmentally friendly, and LiMn2O4 a high-voltage discharge, the technology is mature, security, and other layered structure of the cathode material can not be compared High-rate charge and discharge capacity of the advantages and thus present in the promotion of lithium-powered batteries, LiMn2O4 has great advantages. Although relatively lower than capacity, but the larger battery is not in itself constitute a significant weakness. LiMn2O4 cathode materials for the lithium-ion batteries assembly has a good safety and thermal stability. However, there are also LiMn2O4 capacity fading fast (especially in high-temperature conditions), the short life cycle of the shortcomings that impedes the process of actually used. Nickel and cobalt LiMn2O4 material than are the advantages of high capacity, superior performance cycle. Made of lithium-ion battery has a very high energy density, suitable for severe restrictions on weight and volume but high-energy requirements of the field. As the use of the cobalt, nickel and other metals, nickel and cobalt prices LiMn2O4 after LiCoO2. However, nickel and cobalt manganese lithium-acid battery applications in force yet to be assessed on the domestic application of the material is usually the way through doping modified to improve its safety performance, but did not see the size of the application. Lithium iron phosphate rich source of raw materials, low prices, higher than the capacity and excellent high-temperature cycle performance and high safety performance advantages, is very dynamic development prospects of battery cathode materials. Lithium iron phosphate as a new type of battery cathode materials for use in recent years have warming trend. Since the patent restrictions, Europe and North America to mass production of lithium iron phosphate battery of small manufacturers, IBM ThinkPad R50 Battery basically been monopolized by a few manufacturers. Although many domestic manufacturers of lithium-ion iron phosphate lithium battery research and development into production, but due to technical and system-level differences in product quality varied. Additives, electrolyte safety Lithium-ion battery power also affected the design of the IBM ThinkPad R51 Series Battery of security. Only manufacturers are in the negative ratio, bonding agent types, divide the assembly, welding and a type of ear, package, through careful calculation and control, to make a film within a reasonable current distribution, polarization small battery, cooling Good and efficient security. For safety considerations, the driving force in the design of the battery would normally be taken into account when the abnormal situation occurs when the battery system to environmental heat transfer rate system can produce heat than the speed, because it determines the heat out of control in response to the probability . To further enhance the safety of battery power, many manufacturers will normally be the electrolyte in the battery to join the functional additives. These additives have been sufficient defense, anti-Expansion to improve the low temperature and the role of fire-retardant. It is worth mentioning that the flame retardant electrolyte add impetus to enhance the safety of the battery an important direction. Join the flame retardant is designed to increase the oxygen for combustion electrolyte. As we all know, when the oxygen index of more than 27 when a flame retardant material, the development of the flame retardants are close to or reach this target. The power battery electrolyte, the individual indexes for the development of the additive is not difficult, the difficulty of the electrolyte is to ensure that security at the same time we must take into account other conventional performance. Electrolyte balance for the function, multi-functional compound additives on the direction of R & D is. Essential to the protection board In order to strengthen the driving force for the safety of lithium-ion battery, battery protection board is bound with the equipment. In most cases, lithium protection board should have control of the use of lithium-ion battery conditions of work functions, these conditions include voltage, current and temperature. As the use of lithium-ion batteries are unique, making lithium-ion battery power to protect and support the use of panels together to ensure the safety and reliability of the system as a whole. More and more strings of batteries in matching assembly, in the process of long-term use is inevitable that there are individual differences, the protection board (or battery management system) to be responsible for the entire group of battery voltage, current and temperature, and even the IBM FRU 08K8193 Battery capacity to monitor, we must Achieve the accuracy and prompt action can play a due role. At the same time, battery performance of individual differences in the same charge and discharge current, sections of the battery voltage and available capacity will be different, with the increase in the number of cycle, the battery performance differences will become increasingly significant, which will Greatly reduced performance of the entire battery life significantly shortened. For battery performance to reach or approach the level of single cells, each cell must be balanced so that the batteries within the single charge and discharge performance deteriorated due to reduce to the minimum extent. Most manufacturers have adopted a balanced protection of rechargeable lithium-ion batteries for maintenance. Therefore, the driving force for the safety of lithium-ion battery of factors, the electrode material is essential, to ensure that meet the current industry standard materials testing system only LiMn2O4 and lithium iron phosphate. Manufacturers generally use the safety and compatibility of good performance additives protect the electrolyte lithium-ion battery power to better use. In addition, lithium-ion protection board provides for the protection of the functions of lithium batteries, can maximize the protection of safe and reliable power battery use. Charge balance function of practical guarantee for the lithium-ion battery to power high-securitylong-life work. From the future trend, power lithium-ion batteries, boards and equipment for the protection of the three joint development is a scientific development.