Charging method for prolonging cycle life of lithium iron phosphate battery

Abstract

The invention discloses a charging method for prolonging the cycle life of a lithium iron phosphate battery, and relates to the technical field of battery charging, the method comprises the following stages: a first stage: determining the maximum charging rate C0 of the cycle of the lithium iron phosphate battery; in the second stage, the cut-off voltage U0 and the maximum cut-off voltage Umax of the first stage of high-rate charging are determined according to the maximum charging rate C0; in the third stage, constant-current charging is conducted to the maximum cut-off Umax according to the standard charging rate C standard, then discharging is conducted to the preset cut-off voltage U1 according to the discharging rate C standard, the original capacity C1 is divided, then constant-current charging is conducted to the cut-off U0 according to the maximum charging rate C0, discharging is conducted to the cut-off U0 according to the standard discharging current, the capacity C2 is divided, and the battery cell electric quantity SOC of the lithium iron phosphate battery at the moment is calculated, and in the fourth stage, the SOC is charged with C3 in a constant current mode, then the SOC is fully charged with C4 and Umax in a constant current and constant voltage mode, and C4 is smaller than C3. According to the method, the circulation of the cylindrical lithium iron phosphate material battery can be correspondingly improved, and meanwhile, the actual charging time of the battery can be properly shortened.

Description

technical field [0001] The invention relates to the technical field of battery charging, in particular to a charging method for improving the cycle life of a lithium iron phosphate battery. Background technique [0002] Lithium-ion battery is a new type of green and environmentally friendly chemical power source that appeared in the early 1990s. It has the advantages of high voltage, large specific energy, stable discharge voltage, good cycle performance, excellent safety performance, and long storage and working life. It is one of the latest development directions of the chemical power supply industry, and cylindrical batteries are widely used as power batteries. , Involving many fields, such as electric bicycles, electric vehicles, electric drills, etc. [0003] At present, batteries are widely used in the market, and people's consumption concepts are also changing. Fast charging, durability, safety, and long mileage are the common needs of ordinary consumers. To solve th...

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Problems solved by technology

[0003] At present, batteries are widely used in the market, and people's consumption concepts are also changing. Fast charging, durability, safety, and long mileage are common needs of ordinary consumers. To solve the above problems, the introduction of fast charging on batteries Technology and improving the energy density of single batteries are one of the ways to solve the above problems, and fast charging technology can save the actual charging time of batteries, improve the energy density of single batteries, and increase the cruising range of batteries or battery packs, while phosphoric acid Lithium iron battery has its unique advantages, such as safety and long cycle life, but at the same time, the compaction of iron phosphorus is low, and the energy density of the whole battery is low. In order to improve the energy density and charging speed of the single battery, it is easy to cause structural damage. damage, thereby shortening its cycle life

[0004] In the prior art, the 0.5C current standard charging method is generally used for lithium iron phosphate batteries, which takes a long time to charge and has a relatively low cycle life.

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