It is still very urgent and challenging to simultaneously develop high‐rate and long‐cycle oxide cathodes for sodium‐ion batteries (SIBs) because of the sluggish kinetics and complex multiphase ...evolution during cycling. Here, the concept of accurately manipulating structural evolution and formulating high‐performance heterostructured biphasic layered oxide cathodes by local chemistry and orbital hybridization modulation is reported. The P2‐structure stoichiometric composition of the cathode material shows a layered P2‐ and O3‐type heterostructure that is explicitly evidenced by various macroscale and atomic‐scale techniques. Surprisingly, the heterostructured cathode displays excellent rate performance, remarkable cycling stability (capacity retention of 82.16% after 600 cycles at 2 C), and outstanding compatibility with hard carbon anode because of the integrated advantages of intergrowth structure and local environment regulation. Meanwhile, the formation process from precursors during calcination and the highly reversible dynamic structural evolution during the Na+ intercalation/deintercalation process are clearly articulated by a series of in situ characterization techniques. Also, the intrinsic structural properties and corresponding electrochemical behavior are further elucidated by the density of states and electron localization function of density functional theory calculations. Overall, this strategy, which finely tunes the local chemistry and orbitals hybridization for high‐performance SIBs, will open up a new field for other materials.
An abnormal heterostructured biphasic layered oxide cathode for sodium‐ion batteries (SIBs) is successfully constructed, and its dynamic formation process, intrinsic structural properties, and electrochemical behavior are elucidated by a series of in situ characterization techniques and density functional theory calculations. The concept of accurately manipulating structural evolution and formulating heterostructured cathode materials by local chemistry and orbital hybridization modulation is further demonstrated.
Optimizing charge transfer and alleviating volume expansion in electrode materials are critical to maximize electrochemical performance for energy storage systems. Herein, an atomically thin ...soft-rigid Co
S
@MoS
core-shell heterostructure with dual cation vacancies at the atomic interface is constructed as a promising anode for high-performance sodium-ion batteries. The dual cation vacancies involving V
and V
in the heterostructure and the soft MoS
shell afford ionic pathways for rapid charge transfer, as well as the rigid Co
S
core acts as the dominant active component and resists structural deformation during charge/discharge. Electrochemical testing and theoretical calculations demonstrate both excellent Na
transfer kinetics and pseudocapacitive behavior. Consequently, the soft-rigid heterostructure delivers extraordinary sodium storage performance (389.7 mA h g
after 500 cycles at 5.0 A g
), superior to those of the single-phase counterparts; and the assembled Na
V
(PO
)
||d-Co
S
@MoS
/S-Gr full cell achieves an energy density of 235.5 Wh kg
at 0.5 C. Our finding opens up a new strategy of soft-rigid heterostructure and broadens the horizons of material design in energy storage and conversion. This article is protected by copyright. All rights reserved.
Layered oxides have become the research focus of cathode materials for sodium‐ion batteries (SIBs) due to the low cost, simple synthesis process, and high specific capacity. However, the poor air ...stability, unstable phase structure under high voltage, and slow anionic redox kinetics hinder their commercial application. In recent years, the concept of manipulating orbital hybridization has been proposed to simultaneously regulate the microelectronic structure and modify the surface chemistry environment intrinsically. In this review, the hybridization modes between atoms in 3d/4d transition metal (TM) orbitals and O 2p orbitals near the region of the Fermi energy level (EF) are summarized based on orbital hybridization theory and first‐principles calculations as well as various sophisticated characterizations. Furthermore, the underlying mechanisms are explored from macro‐scale to micro‐scale, including enhancing air stability, modulating high working voltage, and stabilizing anionic redox chemistry. Meanwhile, the origin, formation conditions, and different types of orbital hybridization, as well as its application in layered oxide cathodes are presented, which provide insights into the design and preparation of cathode materials. Ultimately, the main challenges in the development of orbital hybridization and its potential for the production application are also discussed, pointing out the route for high‐performance practical sodium layered oxide cathodes.
Based on orbital hybridization theory, the challenges of layered oxide cathodes in terms of air stability, high voltage, anion redox chemistry, and improving the intrinsic characteristics through interactions between the 3d/4d transition metal and the O 2p atomic orbitals are summarized. This strategy of modulating orbitals hybridization will promote the development of sodium layered oxide cathodes and its commercialization process.
Layered transition metal oxide (NaxTMO2), being one of the most promising cathode candidates for sodium‐ion batteries (SIBs), have attracted intensive interest because of their nontoxicity, high ...theoretical capacities, and easy manufacturability. However, their physical and electrochemical properties of water sensitivity, sluggish Na+ transport kinetics, and irreversible multiple‐phase translations hinder the practical application. Here, a concept of surface lattice‐matched engineering is proposed based on in situ spinel interfacial reconstruction to design a spinel coating P2/P3 heterostructure cathode material with enhanced air stability, rate, and cycle performance. The novel structure and its formation process are verified by transmission electron microscopy and in situ high‐temperature X‐ray diffraction. The electrode exhibits an excellent rate performance with the highly reversible phase transformation demonstrated by in situ charging/discharging X‐ray diffraction. Additionally, even after a rigorous water sensitivity test, the electrode materials still retain almost the same superior electrochemical performance as the fresh sample. The results show that the surface spinel phase can play a vital role in preventing the ingress of water molecules, improving transport kinetics, and enhancing structural integrity for NaxTMO2 cathodes. The concept of surface lattice‐matched engineering based on in situ spinel interfacial reconstruction will be helpful for designing new ultra‐stable cathode materials for high‐performance SIBs.
The formation process and function mechanism for inhibiting phase transformation and enhancing air stability of surface lattice‐matched engineering based on in situ spinel interfacial reconstruction are studied. This strategy of designing heterostructure with in situ interfacial reconstruction will inspire the exploitation of new chemistries and materials.
Sodium‐ion oxide cathodes with triphase heterostructures have attracted intensive attention, since the sodium‐storage performance can be enhanced by utilizing the synergistic effect of different ...phases. However, the composite structures generally suffer from multiple irreversible phase transitions and high lattice strain because of interlayer‐gliding during the charge/discharge process. Here, the concept of strain engineering via manipulating the local chemistry of heterostructured oxide cathode is proposed to regulate the relevant physical and chemical properties, resulting in highly reversible structural evolution (P2/P3/spinel → P2/P3″/spinel) and low intrinsic stress in the potential window of 1.5–4.0 V. Also, the simple structural evolution at a relatively high cut‐off potential of 4.3 V can be detected by in situ X‐ray diffraction and other electrochemical characterization techniques during Na+ extraction/insertion. Meanwhile, the electrode exhibits a high reversible capacity (169.4 mAh g−1 at 0.2 C) and excellent rate performance from 1.5 to 4.3 V. Overall, this study reveals the mechanisms of regulating local chemistry to realize strain engineering of the cathode materials and paves the way for the further improvement of high‐performance sodium‐ion batteries.
Strain engineering by manipulating the local chemistry of a heterostructured oxide cathode can facilitate phase transformation and suppress lattice strain, resulting in high‐performance sodium‐ion batteries. The concept of local chemistry modulation can also be used to regulate the physical and chemical properties of other electrode materials and further inspire the exploitation of new materials and chemistries in energy storage and conversion.
The early prediction and accurate tracking of the thermal characteristics of the CPU of a server can help avoid thermal failure and runaway due to defects in its thermal design. This study proposes a ...method of thermal monitoring and temperature prediction based on infrared thermocouples. A nine-channel whole-machine thermal monitoring system based on a thermal module is designed. It collects the real-time temperature data of each channel by using the Raspberry Pi platform through the I 2 C protocol and a visual digital interface that can intuitively display the dynamic distribution of the related temperatures. Based on data on the multi-channel historical thermal distribution as well as continuous training on real-time temperature data, an improved linear regression algorithm-based thermal prediction model is proposed to obtain rules governing the thermal characteristics of the CPU during operation. The results of experiments show that the accuracy of the temperature data collected using our proposed method of thermal monitoring can be controlled to within a range of error of 0.15%, with an average range of 0.62%. In addition, the improved linear regression algorithm predicts a good fitness with the empirical values, with a data coincidence of up to 0.96 compared with the traditional linear regression algorithm. The proposed method to monitor the thermal characteristics and predict the temperature of the CPU can provide a reference for the design and thermal diagnosis of high-performance servers.
Rice is the world's most important staple grown by millions of small-holder farmers. Sustaining rice production relies on the intelligent use of rice diversity. The 3,000 Rice Genomes Project is a ...giga-dataset of publically available genome sequences (averaging 14× depth of coverage) derived from 3,000 accessions of rice with global representation of genetic and functional diversity. The seed of these accessions is available from the International Rice Genebank Collection. Together, they are an unprecedented resource for advancing rice science and breeding technology. Our immediate challenge now is to comprehensively and systematically mine this dataset to link genotypic variation to functional variation with the ultimate goal of creating new and sustainable rice varieties that can support a future world population that will approach 9.6 billion by 2050.
Sodium‐ion batteries (SIBs) are considered as a low‐cost complementary or alternative system to prestigious lithium‐ion batteries (LIBs) because of their similar working principle to LIBs, ...cost‐effectiveness, and sustainable availability of sodium resources, especially in large‐scale energy storage systems (EESs). Among various cathode candidates for SIBs, Na‐based layered transition metal oxides have received extensive attention for their relatively large specific capacity, high operating potential, facile synthesis, and environmental benignity. However, there are a series of fatal issues in terms of poor air stability, unstable cathode/electrolyte interphase, and irreversible phase transition that lead to unsatisfactory battery performance from the perspective of preparation to application, outside to inside of layered oxide cathodes, which severely limit their practical application. This work is meant to review these critical problems associated with layered oxide cathodes to understand their fundamental roots and degradation mechanisms, and to provide a comprehensive summary of mainstream modification strategies including chemical substitution, surface modification, structure modulation, and so forth, concentrating on how to improve air stability, reduce interfacial side reaction, and suppress phase transition for realizing high structural reversibility, fast Na+ kinetics, and superior comprehensive electrochemical performance. The advantages and disadvantages of different strategies are discussed, and insights into future challenges and opportunities for layered oxide cathodes are also presented.
Recent progress in layered oxide cathodes for sodium‐ion batteries (SIBs) from air stability, interface chemistry, and phase transition are comprehensively summarized. The intrinsic degradation mechanisms behind electrochemical performance and mainstream modification strategies are systematically sorted out and analyzed. The remaining challenges, promising optimization strategies as well as endeavor directions to break current limitations are also presented for the future design of high‐performance layered oxide cathodes for SIBs.
Non‐aqueous solvents, in particular N,N‐dimethylaniline (NMP), are widely applied for electrode fabrication since most sodium layered oxide cathode materials are readily damaged by water molecules. ...However, the expensive price and poisonousness of NMP unquestionably increase the cost of preparation and post‐processing. Therefore, developing an intrinsically stable cathode material that can implement the water‐soluble binder to fabricate an electrode is urgent. Herein, a stable nanosheet‐like Mn‐based cathode material is synthesized as a prototype to verify its practical applicability in sodium‐ion batteries (SIBs). The as‐prepared material displays excellent electrochemical performance and remarkable water stability, and it still maintains a satisfactory performance of 79.6% capacity retention after 500 cycles even after water treatment. The in situ X‐ray diffraction (XRD) demonstrates that the synthesized material shows an absolute solid‐solution reaction mechanism and near‐zero‐strain. Moreover, the electrochemical performance of the electrode fabricated with a water‐soluble binder shows excellent long‐cycling stability (67.9% capacity retention after 500 cycles). This work may offer new insights into the rational design of marvelous water stability cathode materials for practical SIBs.
An intrinsic stable layered oxide cathode material with absolute solid‐solution reaction, near‐zero‐strain, and marvelous water stability is designed for demonstrating the feasibility of fabricating an electrode with a water‐soluble binder. The electrode using a water‐soluble binder exhibits comparable electrochemical performance to that fabricated with an organic‐solution binder. This work will inspire the exploration of highly water‐stable sodium layered oxide cathode materials.
Cell invasion is a hallmark of metastatic cancer, leading to unfavorable clinical outcomes. In this study, we established two highly invasive lung cancer cell models (A549-i8 and H1299-i8) and ...identified mesoderm-specific transcript (MEST) as a novel invasive regulator of lung cancer. We aim to characterize its biological function and clinical significance in lung cancer metastasis.
Transwell invasion assay was performed to establish high-invasive lung cancer cell model. Immunohistochemistry (IHC) was used to detect MEST expression in tumor tissues. Mass spectrometry and bioinformatic analyses were used to identify MEST-regulated proteins and binding partners. Co-immunoprecipitation assay was performed to detect the interaction of MEST and VCP. The biological functions of MEST were investigated in vitro and in vivo. Immunofluorescence staining was conducted to explore the colocalization of MEST and VCP.
MEST overexpression promoted metastasis of lung cancer cells in vivo and in vitro by activating NF-κB signaling. MEST increased the interaction between VCP and IκBα, which accelerated IκBα degradation and NF-κB activation. Such acceleration was abrogated by VCP silencing, indicating that MEST is an upstream activator of the VCP/IκBα/NF-κB signaling pathway. Furthermore, high expressions of MEST and VCP were associated with poor survival of lung cancer patients.
Collectively, these results demonstrate that MEST plays an important role in driving invasion and metastasis of lung cancer by interacting with VCP to coordinate the IκBα/NF-κB pathway. Targeting the MEST/VCP/IκBα/NF-κB signaling pathway may be a promising strategy to treat lung cancer.
PDF
