Development of core technology of lithium battery pack -Lithium - Ion Battery Equipment
Lithium-ion battery packs are about to reach the technical bottleneck, and solid-state batteries and fuel-powered batteries will be commercialized. Innovative layouts should be used to solve the technical shortcomings of electric vehicles and ease users' mileage anxiety. Until now, the service life of lithium-ion batteries is still unsatisfactory. Battery technology is still the biggest bottleneck in the evolution of all electronic devices. From the perspective of industrialization, battery technology is still a long way from a revolutionary breakthrough. distance.(Lithium - Ion Battery Equipment)
Lithium-ion battery is the representative of modern high-performance battery, which consists of four important parts: positive electrode material, negative electrode material, separator and electrolyte.
Separator is an important part of lithium-ion battery pack, and it is an important component to support lithium-ion battery to complete the electrochemical process of charging and discharging. It is located between the positive and negative electrodes inside the battery, which ensures the passage of lithium ions and hinders the transmission of electrons. The performance of the separator determines the interface structure and internal resistance of the battery, which directly affects the capacity, cycle and safety performance of the battery.
Electrolyte, Li-ion battery electrolyte is generally mixed with high dielectric constant cyclic carbonate and low dielectric constant linear carbonate. Generally speaking, the electrolyte of lithium-ion battery should meet the requirements of high ionic conductivity (10-3~10-2S/cm), low electronic conductivity, wide electrochemical window (0~5V), and good thermal stability (-40~60℃). ) and other requirements. Lithium hexafluorophosphate and other new lithium salts, solvent purification, electrolyte preparation, and functional additive technologies continue to advance. The current development direction is to further increase its operating voltage and improve the high and low temperature performance of batteries. Safe ionic liquid electrolytes and solid electrolytes are under development.
The negative electrode materials that can be used for power lithium-ion battery packs include graphite, hard/soft carbon and alloy materials. Graphite is currently widely used as negative electrode material, and its reversible capacity can reach 360mAh/g. Amorphous hard carbon or soft carbon can meet the needs of batteries in higher rate and lower temperature applications, and are beginning to be used, but it is important to be mixed with graphite. Lithium titanate anode material has the best rate performance and cycle performance, and is suitable for high-current fast-charging batteries, but the produced batteries have low specific energy and high cost.
Lithium iron phosphate battery packs have high safety and long life. At present, nano-sized power materials and high-density lithium manganese iron phosphate materials develop rapidly. The performance of high-energy and high-power materials tends to be stable, and the cost is further It gradually meets the needs of the domestic market and the promotion of new energy vehicles in my country at this stage. High voltage spinel lithium nickel manganese oxide and high voltage and high specific capacity lithium-rich manganese-based cathode materials are still under development.