Contemporary Amperex Technology Co., Ltd.

Ningde Contemporary Amperex Technology Limited

Qinghai Contemporary Amperex Technology Limited

Shilin Huang

Jingyao Mei

Jianguo Hu

Kefei Wang

Chenghua Fu

Pinghua Deng

Junzhong Hu

The invention discloses a passive equalization method for a lithium iron phosphate battery pack, comprising: determining a voltage range in which a State of Charge can be accurately queried for a cell in the battery pack, and determining a corresponding relation between a voltage at which a State of Charge can be accurately queried and the State of Charge; collecting an open circuit voltage of each cell in a quiescent state; judging whether the open circuit voltage is within the voltage range in which a State of Charge can be accurately queried; if the open circuit voltage is within the voltage range in which a State of Charge can be accurately queried, acquiring the State of Charge of the cell corresponding to the open circuit voltage according to the open circuit voltage and the corresponding relation between a voltage at which a State of Charge can be accurately queried and the State of Charge, and determining equalizing capacity of each cell according to the State of Charge of each cell; calculating equalizing discharge current of each cell according to a passive equalization principle, and calculating equalizing discharge time of each cell according to the equalizing capacity and the equalizing discharge current of each cell; and subjecting the battery pack to passive equalization based on the equalizing discharge time of each cell.

Passive equalization method and system for lithium iron phosphate battery pack

The present application relates to an active equalization method and system of a lithium iron phosphate (LFP) battery pack. The method includes the following steps of: determining, for each cell in the LFP battery pack, a voltage range in which a State of Charge (SoC) can be accurately queried, and determining a corresponding relation between a voltage at which the SoC can be accurately queried and the SoC; sampling an open circuit voltage of each cell in the LFP battery pack in a quiescent state; judging whether the open circuit voltage is within the voltage range in which the SoC can be accurately queried; if the open circuit voltage is within the voltage range in which the SoC can be accurately queried, acquiring the SoC of a cell corresponding to the open circuit voltage according to the open circuit voltage and the corresponding relation between the voltage at which the SoC can be accurately queried and the SoC, and determining an equalized capacity of each cell according to the SoC of each cell; performing active equalization processing on the LFP battery pack based on the equalized capacities of respective cells in the LFP battery pack.

Active equalization method and system of lithium iron phosphate battery pack

A lithium ion battery electrolyte, comprises lithium salt, a non-aqueous organic solvent and additives. The additives comprise an SEI film forming additive and furil and derivatives thereof, and the SEI film forming additive is at least one of vinylene carbonate, fluoroethylene carbonate and vinyl ethylene carbonate. Compared with the prior art, furil and derivatives thereof are added to the electrolyte as electrolyte additives in the present invention, to enhance the permeability for separator and the wettability for positive/negative electrode materials, facilitate the film forming reaction of the SEI film forming additive, and further improve the cycling performance of the lithium ion battery using the electrolyte. Furthermore, the furil and derivatives thereof have good chemical and electrochemical stability and free from decomposition reaction within the operating voltage range of the lithium ion battery, thereby imparting no negative effect upon battery performances.

Lithium ion battery and electrolyte thereof

The present disclosure provides a lithium-ion battery and a deformable safety valve as an overcharge protection device thereof. The deformable safety valve as the overcharge protection device of the lithium-ion battery comprises a short-circuit conductive plate and a deformable plate made from aluminum, a facing surface of the deformable plate being coated with a metal layer to reduce contact resistance between the deformable plate and the short-circuit conductive plate. The lithium-ion battery comprises a first electrode post; a cap plate electrically connected to the first electrode post; an electrolyte-injection hole provided in the cap plate; a vent provided in the cap plate; a deformable safety valve provided to the cap plate; and a second electrode post assembled to the cap plate in an insulating manner; wherein the deformable safety valve is the above deformable safety valve as the overcharge protection device of the lithium-ion battery.

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Ningde, China

Shilin Huang