Multi-objective planning and optimization of microgrid lithium iron phosphate battery energy storage system consider power supply status and CCER transactions

Lithium iron phosphate battery (LIPB) is the key equipment of battery energy storage system (BESS), which plays a major role in promoting the economic and stable operation of microgrid. Based on the advancement of LIPB technology and efficient consumption of renewable energy, two power supply planning strategies and the china certified emission reduction (CCER) model are proposed respectively. Based on it, the multi-objective planning optimization model with economic benefits, environmental benefits and power supply stability as the objective function is established for the first time, and the Newton Weighted Sum Frisch method (NWSFA) solution model is adopted. In the planning process, rain flow counting method is used to research the life of BESS, which improves the accuracy of energy storage annual cost calculation. A park in northern China is taken as a case study to demonstrate the application of this model. The simulation results show that the annual economic operating cost of BESS is decreased by 18.81%, the energy supply reliability is increased by 0.15%, and the optimal electricity price adjustment ratio of the system is 15%.     

Electrochemical performance of spherical Li-rich LMNCO cathode materials prepared using a two-step spray-drying method

In this study we synthesized Li-rich Li_1.2Ni_0.13Mn_0.54Co_0.13O₂ (LMNCO) as a composite cathode material through a two-step spray-drying method, using transition metal (TM) acetates and citric acid (CA, as a chelating agent) at various molar ratios and then calcining at various temperatures for various periods of time. This two-step spray-drying method created hierarchical nano/micro-sphere structures of the LMNCO cathode material. The LMNCO cathode exhibited the best electrochemical performance when synthesized with a TM:CA ratio of 3:2, a calcination temperature of 900 °C, and a calcination time of 5 h. This as-prepared LMNCO composite was then modified with polyimide (PI) at various weight ratios (PI/LMNCO = 0.5, 1.0, and 1.5 wt%) to improve its electrochemical properties. Among the various structures, the LMNCO cathode material coated with 1.0 wt% of PI at a layer thickness of approximately 1.88 nm achieved the best initial discharge capacities. This modified electrode also displayed enhanced cycle stability, with over 93.3 and 87.9% of the capacity retained after 30 cycles at 0.1C and 100 cycles at 1C, respectively. In comparison, the capacity retention of the unmodified LMNCO electrode measured under the same conditions was no more than 91.3% at 0.1C and 70.1% at 1C. Thus, surface modification with PI was an effective method for improving the coulombic efficiency, discharge capacity, and long-term cycling performance of the LMNCO cathode. Such PI-coated LMNCO composite cathode materials appear to be potential candidates for use in next-generation high-performance lithium-ion batteries.     

模具设计与制造专业群虚拟仿真实训基地建设路径研究

针对模具设计与制造专业群实训教学开展过程中存在的问题,开展专业群虚拟仿真实训基地的建设,通过精密模具智能制造生产线仿真实训工厂、模具数字化设计及智能成型单元综合应用平台、开放共享课程资源等3个方面内容的建设,引入行业新技术、新工艺、新标准,确保虚拟仿真教学资源与学生职业能力培养相一致。基地建设依托智能制造新技术,以培养高层次复合型技术技能人才为主线,满足实训教学为核心,多方共享为目标,助力区域经济发展,服务"鲁班工坊"国际化建设,最终实现虚拟仿真实训基地区域示范性效果。     

改进的CAGAN在虚拟试衣中的应用

针对CAGAN（Conditional Analogy GAN）换衣后效果模糊，在目标衣服与原始衣服长短不一致时效果一般，相对目标衣服保留过少的细节等问题做了相关研究并对CAGAN进行了改进，提出了新的虚拟试衣方式。经过改进的CAGAN生成一个粗糙的结果，由该结果得到目标衣服穿在模特身上改变形状后的mask，接下来利用mask对目标衣服进行变形，综合变形的衣服和第一步的结果便得到最终的试衣图像。实验结果表明，该方法解决了前面存在的问题，而且取得了非常好的效果。     

Fracture behavior of solid electrolyte LATP material based on micro-pillar splitting method

The NASICON type solid electrolyte LATP is a promising candidate for all-solid-state Li-ion batteries considering energy density and safety aspects. To ensure the performance and reliability of batteries, crack initiation and propagation within the electrolyte need to be suppressed, which requires knowledge of the fracture characteristics. In the current work, micro-pillar splitting was applied to determine the fracture toughness of LATP material for different grain orientations. The results are compared with data obtained using a conventional Vickers indentation fracture (VIF) approach. The fracture toughness obtained via micro-pillar splitting test is 0.89 ± 0.13 MPa?m^1/2, which is comparable to the VIF result, and grain orientation has no significant effect on the intrinsic fracture toughness. Being a brittle ceramic material, the effect of pre-existing defects on the toughness needs to be considered.     

Cognitive and affective processes for learning science in immersive virtual reality

As immersive virtual reality (IVR) systems proliferate in classrooms, it is important to understand how they affect learning outcomes and the underlying affective and cognitive processes that may cause these outcomes. Proponents argue that IVR could improve learning by increasing positive affective and cognitive processing, thereby supporting improved performance on tests of learning outcome, whereas opponents of IVR contend that it could hurt learning by increasing distraction, thereby disrupting cognitive learning processes and leading to poorer learning outcomes. In a media comparison study, students viewed a biology lesson either as an interactive animated journey in IVR or as a slideshow on a desktop monitor. Those who viewed the IVR lesson performed significantly worse on transfer tests, reported higher emotional arousal, reported more extraneous cognitive load and showed less engagement based on EEG measures than those who viewed the slideshow lesson, with or without practice questions added to the lessons. Mediational analyses showed that the lower retention scores for the IVR lesson were related to an increase in self-reported extraneous cognitive load and emotional arousal. These results support the notion that immersive environments create high affective and cognitive distraction, which leads to poorer learning outcomes than desktop environments.     

A matryoshka-like CuS@void@Co3O4 double microcube-locked sulfur as cathode for high-performance lithium-sulfur batteries

Lithium-sulfur battery cathodes still remain a challenge on capacity decay due to the shuttle effect even though a series of strategies have been tried. Here we report a novel matryoshka-like CuS@void@Co₃O₄ architecture of double micro-cubes (μ-cubes) that locks sulfur between the CuS core and the Co₃O₄ shell. Plenty of existing spaces between the μ-cubes suffice a high loading of sulfur and volumetric accommodation. The robust, double closed cubes configuration greatly enhances the confinement of polysulfides. In parallel, the CuS core increases the electronic conductivity and contributes to additional capacity, while the Co₃O₄ shell ensures a better interface activity. A high Li⁺ ion diffusion coefficient is obtained during the sulfur and lithium sulfide transformation. The constructed battery displays an initial capacity up to 1480 mAh g⁻¹, and a Coulombic efficiency (CE) exceeding 99%. A capacity retention higher than 500 mAh g⁻¹ with a CE larger than 99.8% after cycling 400 times at 0.2 C are achieved. In addition, under a temperature of −5 °C, a high capacity of 700 mAh g⁻¹ at 0.2 C after 200 cycles is achieved, indicating a good low-temperature tolerance.     

Sea urchin-like LiAlO2@NiCoO2 hybrid composites with core-shell structure as high-performance Li storage materials

Sea urchin-like LiAlO₂@NiCoO₂ hybrid composites with core-shell structure assembled with nanoneedles have been successfully fabricated through a facile hydrothermal route followed by a calcination procedure in N₂ for the first time. The sea urchin-like architecture with large accessible surface can offer numerous active sites for redox reaction. The synergy of two advantages has dramatically improved the electrochemical behavior in terms of specific capacity, cycle performance and rate capability, especially at high current densities. The LiAlO₂(5.0 wt%)@NiCoO₂ displays charge capacities are 1309.0 and 933.6 mAh g^?1 at 0.5 and 1A g^?1, respectively, after 400 cycles. However, the charge capacities of bare NiCoO₂ are only 562.9 and 476.7 mAh g^?1 at corresponding rates. Especially, LiAlO₂(5.0 wt%)@NiCoO₂ preserves 358.1 mAh g^?1 after 500 cycles at 2A g^?1 with a capacity retention of 74%. The superior electrochemical property is related to the sea urchin-like nature and the ingenious composition design. In addition, the DFT calculation result shows that the formed stable, well-coordinated, and metallic interface between LiAlO₂ and NiCoO₂ are very helpful for reducing the interfacial impedance and beneficial for the improved rate capability of the materials. Therefore, such LiAlO₂@NiCoO₂ composites with unique morphology demonstrate a huge potential as electrode materials for Li-ion batteries.     

Recycling spent lead acid batteries into aqueous zinc-ion battery material with ultra-flat voltage platforms

The harmless disposal of lead paste in the spent lead-acid batteries (LABs) remains an enormous challenge in traditional pyrometallurgical recycling. Here, we introduced a hydrometallurgical method for the recycling of the spent LABs’ waste to obtain the β-PbO as a novel zinc ion batteries (ZIBs) active material. The obtained β-PbO exhibits ultra-flat charge/discharge voltage platforms (0.21 mV/(mAh g^?1)) and stable specific capacity. During the charge/discharge, the β-PbO spontaneously triggers the formation of (ZnSO₄)[Zn(OH)₂]₃·5H₂O (ZHS) micro-sheets as a surface passivation layer. Moreover, the ex-situ X-ray spectra reveal that the reversible phase transformation occurs between PbSO₄ and Pb with the assistance of ZHS by adjusting the PH value on the electrode-electrolyte interface. The synergistic two-phase-reaction mechanism generates ultra-flat voltage platforms upon the charge/discharge. This “energy-saving and environment-friendly” recycling route eliminates the major source of emission of pollution particulates/gases compared to the traditional pyrometallurgical recycling, while at the same time replacing energy-consuming and environmentally detrimental processes of synthesis of current ZIBs cathodes.     

Corrosion of Li-ion battery cathode materials on mullite insulation materials during calcination

A specially designed experimental device was used in laboratory to investigate the corrosion of mullite during the calcination of Li(Ni_xCo_yMn_z)O₂ (LNCM) materials. The anti-corrosion tests were carried out at 1000, 1100, 1200 and 1300 °C, and characterized with X-ray diffraction and scanning electron microscopy. The influence of temperature on the interactions between mullite insulation materials and LNCM materials was determined. In addition, the high-temperature creep properties of the mullite insulation materials before and after corrosion were tested. The laboratory scale tests, thermodynamic and kinetic calculations allowed a more comprehensive understanding of the evolution of the mullite insulation materials during serving for the roasting process of LNCM materials. Through this research, it is suggested that the upgrading of the kiln lining in the lithium battery industry should select materials with excellent resistance to alkali corrosion, especially excellent resistance to Li⁺ corrosion.