Abstract: A negative electrode plate, a secondary battery, a battery module, a battery pack, and an electrical device are provided. The negative electrode plate includes a negative current collector and a negative film layer disposed on the negative current collector. The negative film layer includes a first negative film layer and a second negative film layer. The second negative film layer is located between the negative current collector and the first negative film layer. The second negative film layer includes a metal element M, and an atomic radius rM of M and an atomic radius rLi of Li satisfy 0 < ? "\[LeftBracketingBar]" r M - r Li r Li ? "\[RightBracketingBar]" × 100 ? % ? 12 ? % . This application can effectively suppress precipitation of lithium metal on the surface of the negative electrode plate, and significantly improve kinetic performance, cycle performance, and safety performance of the secondary battery.

Abstract: The present application provides a secondary battery including a negative electrode sheet, and the negative electrode sheet includes: a negative electrode current collector; a first negative film layer provided on at least one surface of the negative electrode current collector; and a second negative film layer provided on a surface of the first negative film layer; where the first negative film layer includes a first negative active material and a first conductive agent, and the first negative active material includes a silicon-based material; and a mass proportion of the silicon-based material in the first negative film layer is greater than or equal to 30%, and a mass proportion of the first conductive agent in the first negative film layer is greater than or equal to 25%. A battery cell of the secondary battery of the present application does not easily expand and has good cycle performance.

Abstract: An artificial graphite satisfies: PD5 t/PD0.5 t ? 1.35, where PDst is a compacted density of the artificial graphite measured under a pressure of 5 ton, and PD0.5 t is a compacted density of the artificial graphite measured under a pressure of 0.5 ton.

Abstract: Systems, methods, and apparatuses for protecting a secret on a device with limited memory, while still providing tamper resistance, are described. To achieve security, an encoding computer can apply a memory-hard function MHF to a secret S and determine a result Y, then determine a proof ? for the result Y. Then, the encoding computer can send a codeword C comprising the secret S and the proof ? to a decoding computer. The decoding computer can retrieve the codeword C from persistent memory and parse the secret S and the proof ?. The decoding device can use transient memory to decode the codeword C by verifying the proof ? was generated with the secret S and the result Y. When the correctness of the result Y is verified, the decoding device can apply a cryptographic function to input data using the secret S then reset the transient memory.

Abstract: Systems, methods, and apparatuses for protecting a secret on a device with limited memory, while still providing tamper resistance, are described. To achieve security, an encoding computer can apply a memory-hard function MHF to a secret S and determine a result Y, then determine a proof ? for the result Y. Then, the encoding computer can send a codeword C comprising the secret S and the proof ? to a decoding computer. The decoding computer can retrieve the codeword C from persistent memory and parse the secret S and the proof ?. The decoding device can use transient memory decode the codeword C by verifying the proof ? was generated with the secret S and the result Y. When the correctness of the result Y is verified, the decoding device can apply a cryptographic function to input data using the secret S then reset the transient memory.