Abstract: An electrolyte solution includes an electrolyte salt, a solvent, and a polyether. A secondary battery includes the electrolyte solution. A method for preparing a secondary battery electrolyte solution includes adding an additive and a cyclic ether compound into a composition containing an electrolyte salt and a solvent, and performing in-situ polymerization for at least 24 hours to obtain the secondary battery electrolyte solution. The additive is a Lewis acid or a Lewis acid precursor.

Abstract: A secondary battery, an electrolyte, and an electric apparatus. The secondary battery includes a positive electrode plate, an electrolyte, a separator, and a negative electrode current collector, where the electrolyte includes a non-aqueous solvent, an electrolytic salt, and an additive; the non-aqueous solvent includes an ether organic solvent; the additive includes a first additive; and the first additive includes one or more of a phosphite additive or a borate additive.

Abstract: An electrolyte, a sodium secondary battery and an electric device. The electrolyte comprises a first sodium salt and a first solvent, wherein the first sodium salt comprises sodium trifluoromethanesulfonate, and the first solvent has a structure as shown in formula I, with the mass ratio of the first sodium salt to the first solvent being 0.01-0.4. The electrolyte has a good low-temperature ionic conductivity, which is beneficial for improving the low-temperature cycling performance and low-temperature coulombic efficiency of the battery.

Abstract: The present application provides a sodium ion battery, comprising a positive electrode plate, a negative electrode plate and an electrolyte. The negative electrode plate comprises a negative electrode current collector and a primer coating layer formed on the surface of the negative electrode current collector. The electrolyte comprises a first sodium salt, and the first sodium salt includes at least one of a sulfur-containing organic sodium salt and a boron-containing organic sodium salt, and the sodium ion battery satisfies the following relationship: 0.84?Y?0.01X?5.84, wherein X g/m2 is the areal density of the primer coating layer, and Y % is the mass content of the first sodium salt, based on the total mass of the electrolyte.

Abstract: A current collector with a coating, a secondary battery, a battery module, a battery pack, and an electrical device are disclosed. The coating includes at least a surface modification layer. The coating is formed on at least one side of the current collector. A thickness of the surface modification layer is 100 nm to 10 ?m. The coating formed on at least one side of the current collector can effectively block direct contact between a negative electrode metal and an electrolyte solution constituent, thereby reducing side reactions between the negative electrode metal and the electrolyte solution, significantly reducing gas generated by the battery during cycling, and improving the cycle performance and safety of the battery.

Abstract: This application provides a current collector with a coating, a secondary battery, a battery module, a battery pack, and an electrical device. The coating includes at least a surface modification layer. The coating is formed on at least one side of the current collector. A thickness of the surface modification layer is not greater than 50 nm. The coating formed on at least one side of the current collector can effectively block direct contact between a negative electrode metal and an electrolyte solution constituent, thereby reducing side reactions between the negative electrode metal and the electrolyte solution, significantly reducing gas generated by the battery during a long period of cycling, and improving the cycle performance and safety of the battery.

Abstract: A sodium metal battery cell and a preparation method thereof, a battery, and an electrical device. The sodium metal battery cell includes: an electrolyte solution, where the electrolyte solution includes a first additive, and the first additive includes an organic compound containing an unsaturated group; and a catalyst, where the catalyst includes at least one of a transition-metal pure element or an alloy thereof.

Abstract: An electrolyte for sodium secondary battery, a sodium secondary battery, a battery module, and an electric apparatus. The electrolyte for sodium secondary battery includes a sodium salt, an ether solvent, and a fluoroether solvent. The electrolyte includes ether solvent molecules and fluoroether solvent molecules that form a co-solvation structure with sodium ions.

Abstract: An electrolyte for a sodium secondary battery, the sodium secondary battery, and an electric device. The electrolyte for the sodium secondary battery includes a diluent, where the diluent includes an alkyl alkoxy silane compound. The sodium secondary battery includes the electrolyte described above. The electric device includes the sodium secondary battery described above.

Abstract: An electrolyte solution includes an electrolyte salt, a solvent, and a polyether. A secondary battery includes the electrolyte solution. A method for preparing a secondary battery electrolyte solution includes adding an additive and a cyclic ether compound into a composition containing an electrolyte salt and a solvent, and performing in-situ polymerization for at least 24 hours to obtain the secondary battery electrolyte solution. The additive is a Lewis acid or a Lewis acid precursor.

Abstract: This application provides an electrolyte for a sodium secondary battery, a sodium secondary battery, and an electrical apparatus. An electrolyte for a sodium secondary battery is provided, where the electrolyte includes an additive, and the additive includes a fluorinated ether compound. In this application, through the addition of an additive, including a fluorinated ether compound, in the electrolyte, the high-temperature cycling performance of the battery can be improved, the high-temperature gas generation phenomenon of the battery can be alleviated, and the electrochemical performance and safety performance of the battery can be improved.

Abstract: This application provides an electrolyte for a sodium secondary battery, a sodium secondary battery, and an electric device. An electrolyte for a sodium secondary battery is provided, where the electrolyte includes an additive, and the additive includes a sulfate ester compound or a sulfonate ester compound. In this application, through the addition of an additive, including a sulfate ester compound or a sulfonate ester compound, in the electrolyte, the high-temperature cycling performance of the battery can be improved, the high-temperature gas generation phenomenon of the battery can be alleviated, and the electrochemical performance and safety performance of the battery can be improved.

Abstract: This application provides a sodium secondary battery electrolyte, a sodium secondary battery, and an electric apparatus. The sodium secondary battery electrolyte is provided, and the electrolyte includes a diluent, where the diluent includes alkane with a formula CnH2n+2, where n is 8 to 13. The diluent can improve high-temperature cycling performance of a battery, reduce high-temperature gas production of the battery, and enhance electrochemical performance and safety performance of the battery at high temperature.

Abstract: A sodium secondary battery includes a positive electrode plate, a negative electrode plate, a first electrolyte located on the side of the positive electrode plate, and a second electrolyte located on the side of the negative electrode plate, where the first electrolyte and the second electrolyte contain different organic solvents, the first electrolyte contains an ester solvent, a sulfone solvent, or a fluoroether solvent, and the second electrolyte contains an ether solvent or an amide solvent. With different organic solvents matched with the positive/negative electrode plate respectively, the electrochemical stability window width of the battery is optimized while gas generation and swelling of the battery are alleviated.

Abstract: A solid electrolyte, a preparation method thereof, a secondary battery, a battery module, a battery pack, and an electric apparatus are described. The solid electrolyte includes a compact layer and a porous layer located on at least one side of the compact layer, where a porosity of the porous layer is greater than a porosity of the compact layer. The porous layer helps to improve the wettability of an interface between the solid electrolyte and a positive electrode plate/negative electrode plate, and also facilitates filling of positive and negative electrode active substances into pores, thereby reducing interface resistance of a battery and improving rate performance and low-temperature performance of the battery.

Abstract: This application provides a sodium secondary battery electrolyte, a sodium secondary battery, and an electrical device. The sodium secondary battery electrolyte includes a solvent. A percentage of an amount of substance of a free solvent in relation to a total amount of substance of the solvent in the electrolyte is not greater than 50%.

Abstract: A solid electrolyte, a secondary battery, a battery module, a battery pack, and an electric apparatus are described. A contact angle of molten sodium on a surface of the solid electrolyte is less than 82°. This helps to improve the interface wettability between the solid electrolyte and a positive electrode plate/negative electrode plate, reduce the interface resistance, improve the interface kinetic performance, and improve the low-temperature performance of the battery.

Abstract: This application provides a current collector and a preparation method thereof, a secondary battery, a battery module, a battery pack, and an electric apparatus. The current collector includes a metal substrate and a surface treatment layer formed on at least one side of the metal substrate, where the surface treatment layer includes oxide and/or nitride of the metal substrate. The surface treatment layer can protect the metal from corrosion by anions in the electrolyte solution or optimize the metal nucleation behavior, improve the coulombic efficiency and cycle capacity retention rate of the battery, and improve the storage performance of the battery.

Abstract: A train positioning method based on a dynamic map includes: performing train positioning initialization based on a positioning source, and obtaining key point information for creating the dynamic map; generating key point coordinates according to the key point information, and creating the dynamic map; updating a train position on the dynamic map according to train displacement and beacon information; updating the dynamic map, and updating the train position based on the updated dynamic map; and, converting an updated train position in the updated dynamic map into a standard track map, to achieve train positioning. A plurality of initialized positioning sources are used to obtain initialization positioning information of train key points, and creation of a dynamic map is completed.

Abstract: A hard carbon. A total quantity of adsorbed nitrogen under a relative pressure P/P0 of nitrogen between 10?8 and 0.035 is V1 cm3 (STP)/g and a total quantity of adsorbed nitrogen under a relative pressure P/Po of nitrogen between 0.035 and 1 is V2 cm3 (STP)/g in a nitrogen adsorption isotherm determined at a temperature of 77 K for the hard carbon. The hard carbon satisfies: V2/V1?0.20 and 20?V1?150, where P represents an actual pressure of nitrogen, and P0 represents a saturated vapor pressure of nitrogen at a temperature of 77 K.