The aging of lithium-ion batteries (LIBs) is a crucial issue and must be investigated. The aging rate of LIBs depends not only on the material and electrochemical performance but also on the working conditions. In order to assess the impact of vehicle driving conditions, including the driving cycle, ambient temperature, charging mode, and trip distance on the battery life cycle, this paper first establishes an electric vehicle (EV) energy flow model to solve the operating parameters of the battery pack while working. Then, a powertrain test is carried out to verify the simulation model. Based on the simulated data under different conditions, the battery capacity fade process is estimated by using a semi-empirical aging model. The mileage (Ф) traveled by the vehicle before the end of life (EOL) of the battery pack is then calculated and taken as the evaluation index. The results indicate that the Ф is higher when the vehicle drives the Japanese chassis dynamometer test cycle JC08 than in the New European Driving Cycle (NEDC) and the Federal Test Procedure (FTP-75). The Ф will be dramatically reduced at both low and high ambient temperatures. Fast charging can increase the Ф at low ambient temperatures, whereas long trip driving can always increase Ф to varying degrees.

Epitaxial and polycrystalline ${\mathrm{Fe}}_3{\mathrm{O}}_4$ films were grown on MgO (100) and Si (100) substrates, respectively, at room temperature by using reactive ion beam deposition. The $M_S$ value of epitaxial ${\mathrm{Fe}}_3{\mathrm{O}}_4$ films was around 310 emu/cm³, and was almost independent of thickness from 45 to 195 nm. The $M_S$ value of polycrystalline films showed significant thickness dependence, which might be attributed to the formation of the initial layer. The Verwey transition at 110 K was observed on 195 nm epitaxial films, and decreased significantly with decreasing thickness. The reduction of the Verwey temperature may be related to the residual strain in the film.

(0002) textured and epitaxial $\mathrm{Zn}{\mathrm{Co}}_{0.07}\mathrm{O}$ films were fabricated at room temperature by ion beam deposition on Si substrates. Hall measurement revealed that $\mathrm{Zn}{\mathrm{Co}}_{0.07}\mathrm{O}$ films were $n$ -type semiconductors with carrier concentrations higher than ${10}^{19}∕{\mathrm{cm}}^3$ . The carrier concentration of $\mathrm{Zn}{\mathrm{Co}}_{0.07}\mathrm{O}$ can be manipulated by controlling the oxygen flow rate during deposition or by postannealing. The saturation magnetization and magnetoresistance ratios strongly depended on the carrier concentration. In addition, epitaxial (0002) $\mathrm{Zn}{\mathrm{Co}}_{0.07}\mathrm{O}$ films, grown on Cu underlayers, showed room-temperature ferromagnetism, which may be potentially used for spintronic devices.

Lithium-ion battery heat generation characteristics during aging are crucial for the creation of thermal management solutions. The heat generation characteristics of 21700 (NCA) cylindrical lithium-ion batteries during aging were investigated using the mathematical model that was created in this study to couple electrochemical mechanisms, heat transfer, and aging loss. These findings indicate that, at the same operating current, the heat generation power of the cell increased significantly with battery aging. This increase was primarily due to the energy loss caused by the growth of the solid–electrolyte interface (SEI) and a reduction in the negative porosity and other physical characteristics of the SEI, such as its ionic conductivity and molar volume, which also had an impact on the heat generation power. By investigating the variations in battery heat generation in different aging modes, the electrochemical mechanisms underlying the effects of aging on battery heat generation can be comprehended in depth.