A lithium ion battery according to the present invention comprises a positive electrode, a negative electrode, a positive electrode lead that is connected to the positive electrode, an insulation tape that covers the positive electrode lead, and an electrolyte solution. The insulation tape comprises a base material layer that is mainly composed of an organic material, and a filler layer that is provided on the base material layer; the filler layer contains an oxide compound of an alkaline earth metal; and the electrolyte solution contains fluorine.

This nonaqueous electrolyte secondary battery is provided with a positive electrode, a negative electrode, and a nonaqueous electrolyte. The nonaqueous electrolyte contains a carboxylic acid ester and lithium bisoxalato borate. The concentration of the carboxylic acid ester is not less than 0.01% by volume but less than 10% by volume relative to the volume of the nonaqueous solvent. In addition, the concentration of the lithium bisoxalato borate is not less than 0.01 M but less than 0.2 M.

This nonaqueous electrolyte secondary battery is provided with a positive electrode, a negative electrode, and a nonaqueous electrolyte. The nonaqueous electrolyte contains a carboxylic acid ester and lithium bisoxalato borate. The concentration of the carboxylic acid ester is not less than 0.01% by volume but less than 10% by volume relative to the volume of the nonaqueous solvent. In addition, the concentration of the lithium bisoxalato borate is not less than 0.01 M but less than 0.2 M.

A method for enhancing battery cycle performance. The method is applied in a battery and includes: charging, at a first stage, the battery at a first-stage current until reaching a first-stage voltage; and charging, at a second stage, the battery at a second-stage current until reaching a second-stage voltage. The second-stage voltage is greater than the first-stage voltage, and the second-stage current is less than the first-stage current. The battery includes an electrolytic solution containing an organic solvent. The organic solvent includes a chain carboxylate compound. A weight percent of the chain carboxylate compound in the organic solvent is 10% to 70%. This application further provides an electronic device. The method can enhance high-temperature cycle and storage performance of the battery.

Various embodiments provide an electrolyte solution, a secondary battery, a battery module, a battery pack and an electric device. In those embodiments, the electrolyte solution includes an electrolyte, a solvent and an additive, the additive including sodium hydrosulfite. Various embodiments improve an overall performance of the secondary battery, for example, initial DCR, storage gas production, a rate performance, or the like.

Various embodiments provide an electrolyte solution, a secondary battery, a battery module, a battery pack and an electric device. In those embodiments, the electrolyte solution includes an electrolyte, a solvent and an additive, the additive including sodium hydrosulfite. Various embodiments improve an overall performance of the secondary battery, for example, initial DCR, storage gas production, a rate performance, or the like.

A method for testing a mechanical performance of a lithium ion battery electrode based on a nano-indentation technology includes following steps: connecting an assembled lithium ion battery with an electrochemical test device and setting different test working conditions, so that cyclic charge and discharge experiments are performed on the battery to obtain an attenuation curve of a battery capacity; disassembling the battery and taking out the electrode; scraping some powder from a surface of the cyclic electrode plate and an initial uncyclic electrode plate, and laying down the powder in cold mounting molds separately, pouring the cold mounting solution into the molds; taking out the samples from the molds respectively after the liquid is completely cured and cooled; detecting a mechanical performance after polishing the samples surfaces and analyzing the mechanical performance decay rule of the electrodes.

A method for testing a mechanical performance of a lithium ion battery electrode based on a nano-indentation technology includes following steps: connecting an assembled lithium ion battery with an electrochemical test device and setting different test working conditions, so that cyclic charge and discharge experiments are performed on the battery to obtain an attenuation curve of a battery capacity; disassembling the battery and taking out the electrode; scraping some powder from a surface of the cyclic electrode plate and an initial uncyclic electrode plate, and laying down the powder in cold mounting molds separately, pouring the cold mounting solution into the molds; taking out the samples from the molds respectively after the liquid is completely cured and cooled; detecting a mechanical performance after polishing the samples surfaces and analyzing the mechanical performance decay rule of the electrodes.

An electrolyte for a lithium-secondary battery including a solvent, a lithium salt and an additive, wherein the additive includes a diamine-based compound, and a lithium-secondary battery including the same.

An electrolyte for a lithium-secondary battery including a solvent, a lithium salt and an additive, wherein the additive includes a diamine-based compound, and a lithium-secondary battery including the same.