Contemporary Amperex Technology Co., Ltd.

Contemporary Amperex Technology (Hong Kong) Limited

Changfeng Bie

Hongyu Liu

Na Liu

Chenghua Fu

Shaocong Ouyang

Xin Sun

Huan Ni

Miaomiao Dong

Xue Leng

Wanqing Cai

Provided is a battery pack. The battery pack includes a first battery cell, a second battery cell, and a third battery cell. A positive electrode active substance of each battery cell is composed of lithium iron phosphate and a low-temperature additive. The low-temperature additive is selected from compounds containing at least two carbonyl groups, which are conjugated with an unsaturated structure or an atom having lone-pair electrons connected with the carbonyl groups. At a temperature lower than or equal to 10° C., a ratio of a discharging capacity of a single cell of the second battery cell to a discharging capacity of a single cell of the first battery cell ranges from 1.003 to 1.12, and a ratio of a discharging capacity of a single cell of the third battery cell to a discharging capacity of a single cell of the second battery cell ranges from 1.005 to 1.15.

Battery pack and electrical device

A positive active material is provided. In some embodiments, the positive material includes: a substrate and a coating layer coating the substrate, wherein the coating layer includes a fast ion conductor layer and a carbon coating layer, the substrate includes more than one compound of formula (I): LiFeM1POformula (I), in formula (I), M1 is more than one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb and Ti, and 0≤a≤0.01; the fast ion conductor layer includes a fast ion conductor of a NASICON structure shown in formula (II), LiFeM2(PO)formula (II), in formula (II), M2 is more than one selected from Ti, Zr, Hf, Ge and Sn with valence of +4, and 0≤b≤1.

Positive active material, lithium ion secondary battery, battery module, battery pack and electric device

A battery pack includes a first battery cell, a second battery cell, and a third battery cell. A positive electrode active substance of each battery cell is composed of lithium iron phosphate and a low-temperature additive. The low-temperature additive is selected from compounds containing at least two carbonyl groups, which are conjugated with an unsaturated structure or an atom having lone-pair electrons connected with the carbonyl groups, and a discharging cut-off voltage of the battery pack at a low temperature has the following rules: discharging cut-off voltages V, V, and Vof the first battery cell, second battery cell, and third battery cell range from 1.95V to 2.1V, from 1.8 V to 2.0V, from 1.6V to 1.9V, respectively, and V, V, and Vsatisfy a relationship of V>V>V

A positive active material made of carbon-coated lithium iron phosphate includes a lithium iron phosphate substrate, and a carbon coating layer on a surface of the substrate. The lithium iron phosphate substrate has a general structural formula LiFeMPO, where M is at least one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb, or Ti, and 0&#x2264;a&#x2264;0.01. A carbon coating factor of the carbon-coated lithium iron phosphate, satisfies 0.81&#x2264;&#x3b7;&#x2264;0.95, where BET1 denotes a specific surface area of mesopore and macropore structures in the carbon-coated lithium iron phosphate, and BET2 denotes a total specific surface area of the carbon-coated lithium iron phosphate.

Carbon-coated lithium iron phosphate positive active material, method for preparing same, positive electrode plate containing same, and lithium-ion battery

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Ningde, China

Changfeng Bie