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High-energy-density lithium manganese iron phosphate for lithium-ion batteries:Progresses,challenges,and prospects

Journal of Energy Chemistry 2025年第1期100卷 1-17页

作者： Bokun Zhang Xiaoyun Wang Shuai Wang Yan Li Libo Chen Handong Jiao Zhijing Yu Jiguo Tu State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Research Institute for Intelligent Wearable Systems The Hong Kong Polytechnic University Hong Kong 9977China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China

The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion *** manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered significant attention as a promising positive electrode material for lithium-ion batteries due to its advantages of low cost,high safety,long cycle life,high voltage,good high-temperature performance,and high energy *** LiMn_(x)Fe_(1-x)PO_(4)has made significant breakthroughs in the past few decades,there are still facing great challenges in poor electronic conductivity and Li-ion diffusion,manganese dissolution affecting battery cycling performance,as well as low tap *** review systematically summarizes the reaction mechanisms,various synthesis methods,and electrochemical properties of LiMn_(x)Fe_(1-x)PO_(4)to analyze reaction processes accurately and guide material ***,the main challenges currently faced are concluded,and the corresponding various modification strategies are discussed to enhance the reaction kinetics and electrochemical performance of LiMn_(x)Fe_(1-x)PO_(4),including multi-scale particle regulation,heteroatom doping,surface coating,as well as microscopic morphology ***,in view of the current research challenges faced by intrinsic reaction processes,kinetics,and energy storage applications,the promising research directions are *** importantly,it is expected to provide key insights into the development of high-performance and stable LiMn_(x)Fe_(1-x)PO_(4)materials,to achieve practical energy storage requirements.

关键词： Lithiummanganese iron phosphate High energydensity Lithium-ionbatteries Reactionmechanism Tap density

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A comprehensive survey on graph neural network accelerators

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Frontiers of Computer Science 2025年第2期19卷 11-29页

作者： Jingyu LIU Shi CHEN Li SHEN School of Computer National University of Defense TechnologyChangsha 410073China Key Laboratory of Advanced Microprocessor Chips and Systems Changsha 410073China

Deep learning has gained superior accuracy on Euclidean structure data in neural *** a result,nonEuclidean structure data,such as graph data,has more sophisticated structural information,which can be applied in neural networks as well to address more complex and practical ***,actual graph data obeys a power-law distribution,so the adjacent matrix of a graph is random and *** processing accelerator(GPA)is designed to handle the problems ***,graph computing only processes 1-dimensional *** graph neural networks(GNNs),graph data is ***,GNNs include the execution processes of both traditional graph processing and neural network,which have irregular memory access and regular computation,*** obtain more information in graph data and require better model generalization ability,the layers of GNN are deeper,so the overhead of memory access and computation is *** present,GNN accelerators are designed to deal with this *** this paper,we conduct a systematic survey regarding the design and implementation of GNN ***,we review the challenges faced by GNN accelerators,and existing related works in detail to process ***,we evaluate previous works and propose future directions in this booming field.

关键词： graph neural network accelerators graph convolutional networks design space exploration deep learning domain-specific architecture

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Automatic Control of Magnetic Helical Microrobots Docking with Target Objects in Liquid Environments

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Journal of Bionic Engineering 2025年第2期22卷 574-584页

作者： Fu Zhao Haoran Rong Lefeng Wang State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin150080China Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin150080China

Bio-inspired magnetic helical microrobots have great potential for biomedical and micromanipulation applications. Precise interaction with objects in liquid environments is an important prerequisite and challenge for helical microrobots to perform various tasks. In this study, an automatic control method is proposed to realize the axial docking of helical microrobots with arbitrarily placed cylindrical objects in liquid environments. The docking process is divided into ascent, approach, alignment, and insertion stages. First, a 3D docking path is planned according to the positions and orientations of the microrobot and the target object. Second, a steering-based 3D path-following controller guides the helical microrobot to rise away from the container bottom and approach the target along the path. Third, based on path design with gravity compensation and steering output limits, alignment of position and orientation can be accomplished simultaneously. Finally, the helical microrobot completes the docking under the rotating magnetic field along the target orientation. Experiments verified the automatic docking of the helical microrobot with static targets, including connecting with micro-shafts and inserting into micro-tubes. The object grasping of a reconfigurable helical microrobot aided by 3D automatic docking was also demonstrated. This method enables precise docking of helical microrobots with objects, which might be used for capture and sampling, in vivo navigation control, and functional assembly of microrobots.

关键词： Magnetic actuation Helical microrobots Visual servo Motion control Docking

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ISOAcc: In-situ Shift Operation-based Accelerator For Efficient in-SRAM Multiplication

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ACM Transactions on Design Automation of Electronic systems 2025年第2期30卷 1-24页

作者： Zhao, Gaoyang Shen, Junzhong Lin, Rongzhen Li, Hua Wang, Yaohua National University of Defense Technology College of Computer Science and Technology Changsha China Key Labtoratory of Advanced Microprocessor Chips and Systems National University of Defense Technology Changsha China

Digital SRAM-based CIM architectures must balance three critical factors: quantized neural network bitwidth, accuracy loss, and computational efficiency, each crucial to optimizing performance and efficiency. In Domain Specific Accelerators (DSAs), flexible and specific hardware design, when incorporated with tailored Power-of-2 (P-2) quantization schemes, addresses this issue. However, in CIMs, the absence of flexible and specific hardware to support dynamic switching between general and tailored quantization schemes hinders the adoption of efficient quantization methods. In this article, we propose the In-situ Shift Operation based Accelerator (ISOAcc) for efficient SRAM-based multiplication. The key idea is to introduce transmission gates near the SRAM array to enable the selection of bits from either the same or the neighbor line when data flows from one row to another. This functionally equals a shift operation. By configuring the transmission gates array in a cascade manner, ISOAcc can support 0 to 15-bit shift with a negligible overhead. The ISOAcc can directly leverage P-2 quantization schemes in hardware, thereby greatly reducing multiplication cycles. We have chosen five well-known neural networks to evaluate ISOAcc. The evaluations show that ISOAcc achieves an average performance improvement of 3.24× and an energy reduction of 75%, compared with the state-of-the-art (SOTA) SRAM-based CIM design, Bit-Parallel. © 2025 Copyright held by the owner/author(s). Publication rights licensed to ACM.

关键词： Static random access storage

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Thrust vector control of Hall thrusters using asymmetrical gas injection

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Journal of Electric Propulsion 2025年第1期4卷 1-26页

作者： Lev, Dan Katz Franco, Daniel Zimmerman, Raul Appel, Leonid Georgia Institute of Technology AtlantaGA30318 United States Rafael Advanced Defense Systems Ltd Haifa3102102 Israel

We present an experimental validation of thrust vector control in a Hall thruster by using asymmetrical gas injection into the thruster discharge channel. We detail the design and operation method of a gas distributor divided into three compartments, each fed by a dedicated mass flow controller. Low power Hall thruster (273 W) was operated, and its plume diverted using uneven gas injection via the mass flow controllers. Axial and lateral thrust were measured to assess thrust vector magnitude and direction. We show that the visual plume deflection is approximately in line with the thrust vector. We show that the direction of thrust could be manipulated in the range of -11° to + 7.3° in the cathode plane, when the positive angles are on the cathode side. Additionally, the thrust and specific impulse are reduced by up to 20% when total mass flow rate is preserved while the efficiency may drop to less than half of the nominal (straight) thrust direction. The thrust and specific impulse are reduced by up to 45% when maintaining a constant anode power while the efficiency may drop to less than half. We also showed that for a constant total mass flow rate, anode power may increase by as much as 80% due to an increase in discharge current at deflection angles greater than + 5°, corresponding to gas starvation in the discharge channel closest to the cathode. On the other hand, large discharge current oscillations, Id,rms/Id > 50%, were observed at deflection angles larger than -10°, when most gas is injected in the discharge channel closest to the cathode. This study validates the possibility to control the thrust vector, to a limited degree, using asymmetrical gas injection into the discharge channel. © The Author(s) 2025.

关键词： Hall thrusters

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Enhancing rheology and mechanical properties of DLP 3D-printed Si_(3)N_(4) materials via composition optimization and gas-pressure sintering

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International Journal of Minerals,Metallurgy and Materials 2025年第5期32卷 1220-1233页

作者： Qing Qin Gang Xiong Lin Han Yujuan Zhang Zhen Shen Changchun Ge Institute of Powder Metallurgy and Advanced Ceramics School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory of Multimodal Artificial Intelligence Systems Beijing Engineering Research Center of Intelligent Systems and TechnologyInstitute of AutomationChinese Academy of SciencesBeijing 100190China

Digital light processing(DLP)is a crucial additive manufacturing(AM)technique for producing high-precision ceramic *** study aims to optimize the formulation of Si_(3)N_(4)slurry to enhance both its performance and manufacturability in the DLP process,and investigate key factors such as particle size distribution,photopolymer resin monomer ratios,and dispersant types to im-prove the slurry’s rheological *** these optimizations,a photosensitive Si_(3)N_(4)slurry with 50vol%solid content was de-veloped,exhibiting excellent stability,and low viscosity(2.48 Pa·s at a shear rate of 12.8 s^(-1)).The effects of gas-pressure sintering on the material’s phase composition,microstructure,and mechanical properties were further explored,revealing that this technique significantly increases the flexural strength of the green sample from(109±10.24)to(618±42.15)*** sintered ceramics exhibited high hard-ness((16.59±0.05)GPa)and improved fracture toughness((4.45±0.03)MPa·m^(1/2)).Crack trajectory analysis revealed that crack deflec-tion,crack bridging,and the pull-out of rod-likeβ-Si_(3)N_(4)grains,are the main toughening mechanisms,which could effectively mitigate crack *** these mechanisms,crack deflection and bridging were particularly influential,significantly enhancing the frac-ture toughness of the Si_(3)N_(4)***,this research highlights how monomer formulation and gas-pressure sintering strengthen the performance of Si_(3)N_(4)slurry in the DLP three-dimensional printing *** work is expected to provide new insights for fabricat-ing complex Si_(3)N_(4)ceramic components with superior mechanical properties.

关键词： additive manufacturing Si_(3)N_(4)slurry low viscosity pressure sintering

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Recent advances in photopolymerization 3D printing of alumina-ceramic

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Progress in Natural Science:Materials International 2025年第1期35卷 1-30页

作者： M.Irfan Hussain Min Xia XiaoNa Ren Zhen Shen Muhammad Jamil Changchun Ge Institute of Powder Metallurgy and Advanced Ceramics School of Material Science and Engineering University of Science and Technology Beijing State Key Laboratory of Multimodal Artificial Intelligence Systems Beijing Engineering Research Center of Intelligent Systems and Technology Institute of AutomationChinese Academy of Sciences College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

Digital light processing(DLP) 3D printing has a huge potential for manufacturing intricate and customized ceramic parts with high precision and cost-effectiveness. Research in this field contributes to material innovation,opening the avenues for new process designs in both scientific and industrial sectors. However, the implementation of DLP 3D printing technology in ceramic research has not yet reached the maturity level as that in polymer and tissue engineering. Necessarily, a holistic in-depth literature reporting the successful integration of alumina ceramics within DLP 3D printing technology is urgently needed. This review, systematic examines recent progress in DLP technology, focusing on photopolymer resins that incorporate UV-sensitive monomers, photoinitiators, and dispersants, as well as their synergistic effects on achieving high-quality printing, desirable material properties, and enhanced performance. Further, the review discusses key factors including post-processing characteristics such as debinding and sintering, which influence microstructure, and defect formation including microcracks, porosity and voids. Finally, the challenges associated with printing and sintering are highlighted,aiming to identify focused focused development pathways and potential solution to optimize outcomes. This analysis clarifies existing challenges and also propsoes future applications for DLP technology in the aluminaceramic field.

关键词： Al2O3 ceramics Applications Digital light processing (DLP) Post-processing Resin

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In Situ Environmental Transmission Electron Microscopy Investigation on LiH Formation Prompted by LiF

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Nano Letters 2025年第20期25卷 8303-8309页

作者： Yu, Xinyang Ruan, Digen Ma, Yuan Zheng, Xuzhi Hua, Ze Shao, Ruiwen Wang, Dazhuang Kang, Zhuo Ren, Xiaodi Qiao, Lijie He, Yang Beijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and Engineering University of Science and Technology Beijing Beijing100083 China Department of Materials Science and Engineering University of Science and Technology of China Anhui Hefei230026 China Academy for Advanced Interdisciplinary Science and Technology State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing100083 China Beijing Advanced Innovation Center for Intelligent Robots and Systems School of Medical Technology Beijing Institute of Technology Beijing100081 China

Lithium hydride is a common but unfavorable component that leads to "dead Li" formation in lithium batteries. Since the hydrogen sources in the batteries are diverse and hardly evitable, unraveling the key factors promoting LiH formation is fundamentally crucial in improving lithium batteries’ cycling stability. Herein, by using in situ environmental transmission electron microscope, we revealed a critical role of lithium fluoride in the LiH formation during the electrochemical deposition of Li in a hydrogen environment, presumably by facilitating the kinetic process of hydrogen dissociation and the LiH nucleation. Ex situ coin-cell studies and DFT calculations corroborate this finding, further suggesting that the commonly used fluorine-rich electrolytes could promote LiH formation. Additionally, the LiH lattices in the dendrites are distorted and likely nonstoichiometric with face-centered cubic structured domains of Li metal. These fundamental insights on the LiH formation may pave the way for enhancing the cycle stability of lithium batteries. © 2025 American Chemical Society.

关键词： Lithium-ion batteries

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On the common mode current reduction in induction motor fed by three-level NPC inverter for pumping photovoltaic application

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International Journal of Power Electronics 2025年第1期21卷 28-45页

作者： Mahmoud, Zouhaira Ben Khedher, Adel LATIS – Laboratory of Advanced Technology and Intelligent Systems Ecole Nationale d’Ingénieurs de Sousse Université de Sousse Sousse4023 Tunisia

The presence of common mode voltage (CMV) poses a significant challenge in motor drive applications. Particularly, for Photovoltaic Pumping (PVP) systems, the high-frequency fluctuations of CMV can induce a common mode current (CMC). These challenges not only diminish the lifespan and the reliability of the motor and PV panel but also present safety problems. This work suggests a novel space vector modulation (SVM) for three level NPC (3L-NPC) converter fed induction machine (IM). The proposed SVM simplifies the 3L space vector diagram (SVD) to six two level (2L) diagrams. The synthesis of the zero voltage vector is then achieved through a virtual approach, combining two active vectors. The principal features of the latter are low complexity, low computation burden, reduced CMV and leakage current with high DC bus utilisation ratio. The feasibility and effectiveness of the suggested SVM scheme is verified through both numerical tests and FPGA-based real time implementation. Copyright © 2025 Inderscience Enterprises Ltd.

关键词： Vectors

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Stability and Stabilization of Sampled-Data Based LFC for Power systems:A Data-Driven Method

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IEEE/CAA Journal of Automatica Sinica 2025年第1期12卷 291-293页

作者： Yu-Long Fan Chuan-Ke Zhang Yong He the School of Automation China University of Geosciences the Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems the Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of Education IEEE

Dear Editor,This letter is concerned with stability analysis and stabilization design for sampled-data based load frequency control(LFC) systems via a data-driven method. By describing the dynamic behavior of LFC systems based on a data-based representation, a stability criterion is derived to obtain the admissible maximum sampling interval(MSI) for a given controller and a design condition of the PI-type controller is further developed to meet the required MSI. Finally, the effectiveness of the proposed methods is verified by a case study.

关键词： Sampled data control systems

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