Study of the Within-Batch TID Response Variability on Silicon-Based VDMOS Devices Xiao Li, Jiangwei Cui, Qiwen Zheng, Pengwei Li, Xu Cui, Yudong Li, and Qi Guo MDPI AG Silicon-based vertical double-diffused MOSFET (VDMOS) devices are important components of the power system of spacecraft. However, VDMOS is sensitive to the total ionizing dose (TID) effect and may have TID response variability. The within-batch TID response variability on silicon-based VDMOS devices is studied by the 60Co gamma-ray irradiation experiment in this paper. The variations in device parameters after irradiation is obtained, and the damage mechanism is revealed. Experimental results show that the standard deviations of threshold voltage, subthreshold swing, output capacitance, and diode forward voltage increase, while the standard deviation of maximum transconductance decreases after irradiation. The standard deviation of on-state resistance is basically unchanged before and after irradiation. By separating the trapped charges generated by TID irradiation, it is found that the deviation of the oxide trapped charges and the interface traps increase with the increase in the total dose. The reasons for the variation in device parameters after irradiation are revealed by establishing the relationship between the trapped charges and the electrical parameters before and after irradiation.
Effects of Pre-Deformation under Tension and Annealing Process on the Microstructure and Properties of Al-6Mg-1.0Mn Extruded Wide Reinforcement Plate Pengwei Li, Qiqiang Han, Wei Sun, Xiangjie Wang, Jianzhong Cui, Rui Wang, Chunzhong Liu, and Min Jiang MDPI AG In order to achieve the combination of mechanical and corrosion properties for the Al-Mg-Mn alloy, a novel combination of pre-deformation under tension and an annealing process was investigated on the microstructure and properties of the Al-6Mg-1.0Mn extruded wide reinforcing plate. This was conducted by means of a tensile test, an intergranular corrosion test, scanning electron microscopy (SEM), and transmission electron microscope (TEM) experiments. The results showed that when the pre-deformation under tension in the range of 10–14%, the corrosion performance is first decreased, and then increases with the increase in temperature, becoming stable at 300 °C. After stabilization annealing at 300 °C for 2 h and then sensitizing at 150 °C for 10–200 h, the intergranular corrosion resistance of the aluminum alloy first decreases and then increases as the sensitization time is prolonged. When the sensitization time exceeds 50 h, the intergranular corrosion resistance is significantly improved. After 14% pretension and stabilization annealing at 300 °C for 2 h, the tensile strength, yield strength, and elongation of the alloy reached 360 MPa, 205 MPa, and 18.5%, and a good combination of strength and corrosion resistance of Al-Mg-Mn alloys could be obtained. These excellent properties were attributed to the continuous distribution of β-phase at the grain boundaries, and the combination of pre-deformation under tension with the annealing process promotes the dynamic precipitation of nanoparticles and the formation of substructure.
Optimization of Synergistic Leaching of Valuable Metals from Spent Lithium-Ion Batteries by the Sulfuric Acid-Malonic Acid System Using Response Surface Methodology Pengwei Li, Shao-hua Luo, Faxian Su, Lin Zhang, Shengxue Yan, Xuefei Lei, Wenning Mu, Qing Wang, Yahui Zhang, Xin Liu,et al. American Chemical Society (ACS) A new environmentally friendly and economical recycling process for extracting metals from spent lithium-ion batteries (LIBs) using sulfuric acid and malonic acid as leaching agents is proposed. By applying Box-Behnken design (BBD) and response surface methodology (RSM) optimization techniques, the global optimal solution of the maximum leaching rate of metals in spent LIBs is realized. The results show that under the optimal conditions of 0.93 M H2SO4, 0.85 M malonic acid, and a liquid/solid ratio of 61 g·L-1, a temperature of 70 °C and 5 vol % of 30% H2O2, 99.79% Li, 99.46% Ni, 97.24% Co, and 96.88% Mn are recovered within 81 min. The error between the theoretical value and the actual value of the metal leaching rate predicted by the regression model is less than 1.0%. Additionally, the study of leaching kinetics reveals that the leaching process of Li, Ni, Co, and Mn in spent cathode materials was affected by the synergistic effect of interfacial mass transfer and solid product layer diffusion. Economic analysis reveals that evaluation index should be fully considered when formulating recovery processes for different metals. This process can reduce the environmental risks of heavy metal disposal and allow the reuse of metals recovered from spent LIBs.
Controllable synthesis of polystyrene microspheres used as template and in-situ carbon source for Li<inf>2</inf>MnSiO<inf>4</inf> cathode material to boost lithium-ion batteries performance Pengqing Hou, Yingdong Qu, Pengwei Li, Qing Wang, and Shao‐Hua Luo Hindawi Limited Polyanion‐type Li2MnSiO4 is considered to be a potential lithium storage material due to its high theoretical capacity, low cost, nontoxicity, and good thermal stability. Unfortunately, pure Li2MnSiO4 has poor conductivity and diffusion rate of Li+, which hinders its wide application in energy storage. In this study, Li2MnSiO4 with inverse opal structure is synthesized by simple sol–gel method, and monodisperse polystyrene microspheres (PS) with uniform and controllable size are prepared by soap‐free emulsion. Additionally, Li2MnSiO4 material with a large specific surface area and mesoporous structure is synthesized by using PS as a template. Specifically, after adding 4 wt% of the PS template, the initial discharge specific capacity of the synthesized Li2MnSiO4 material is 109.9 mAh·g−1 at 0.1 C. Compared with pure Li2MnSiO4, the electrochemical performance of the material synthesized by this process has been significantly improved, which is attributed to the mesoporous structure and large specific surface area that improve the conductivity. Hence, the Li2MnSiO4 cathode material synthesized with PS as a template is expected to become an advanced positive material in lithium energy storage.
Novel P2-type layered medium-entropy ceramics oxide as cathode material for sodium-ion batteries Shengxue Yan, Shaohua Luo, Liu Yang, Jian Feng, Pengwei Li, Qing Wang, Yahui Zhang, and Xin Liu Tsinghua University Press AbstractHigh-entropy oxides (HEOs) and medium-entropy oxides (MEOs) are new types of single-phase solid solution materials. MEOs have rarely been reported as positive electrode material for sodium-ion batteries (SIBs). In this study, we first proposed the concept of the application of MEOs in SIBs. P2-type 3-cation oxide Na2/3Ni1/3Mn1/3Fe1/3O2 (NaNMF) and 4-cation oxide Na2/3Ni1/3Mn1/3Fe1/3−xAlxO2 (NaNMFA) were prepared using the solid-state method, rather than the doping technology. In addition, the importance of the concept of entropy stabilization in material performance and battery cycling was demonstrated by testing 3-cation (NaNMF) and 4-cation (NaNMFA) oxides in the same system. Thus, NaNMFA can provide a reversible capacity of about 125.6 mAh·g−1 in the voltage range of 2–4.2 V, and has enhanced cycle stability. The capacity and decay law of the MEO batteries indicate that the configurational entropy (1.28 R (NaNMFA) > 1.10 R (NaNMF)) of the cationic system, is the main factor affecting the structural and cycle stability of the electrode material. This work emphasizes that the rational design of MEOs with novel structures and different electrochemically active elements may be the strategy for exploring high-performance SIB cathode materials in next-generation energy storage devices.