Uncontrolled dendrites growth and serious parasitic reactions in aqueous electrolytes, greatly hinder the practical application of aqueous zinc‐ion battery. On the basis of in situ‐chemical ...construction and performance‐improving mechanism, multifunctional fluoroethylene carbonate (FEC) is introduced into aqueous electrolyte to construct a high‐quality and ZnF2‐riched inorganic/organic hybrid SEI (ZHS) layer on Zn metal anode (ZMA) surface. Notably, FEC additive can regulate the solvated structure of Zn2+ to reduce H2O molecules reactivity. Additionally, the ZHS layer with strong Zn2+ affinity can avoid dendrites formation and hinder the direct contact between the electrolyte and anode. Therefore, the dendrites growth, Zn corrosion, and H2 evolution reaction on ZMA in FEC‐included ZnSO4 electrolyte are highly suppressed. Thus, ZMA in such electrolyte realize a long cycle life over 1000 h and deliver a stable coulombic efficiency of 99.1 % after 500 cycles.
Multifunctional FEC is introduced into aqueous electrolyte to produce a ZnF2‐riched inorganic/organic hybrid SEI (ZHS) layer on Zn metal anode (ZMA) surface. The hydrolysate of FEC can favorably regulate the solvated structure of Zn2+ to restrict the H2O‐related parasitic reactions. The in situ formed ZHS layer not only realize uniform Zn deposition, but also suppresses ZMA corrosion.
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Rational structure and morphology design are of great significance to realize excellent Na storage for advanced electrode materials in sodium‐ion batteries (SIBs). Herein, a cube‐like core/shell ...composite of single MnS nanocubes (≈50 nm) encapsulated in N, S co‐doped carbon (MnS@NSC) with strong CSMn bond interactions is successfully prepared as outstanding anode material for SIBs. The carbon shell significantly restricts the expansion of the MnS volume in successive sodiation/desodiation processes, as demonstrated by in situ transmission electron microscopy (TEM) of one single MnS@NSC nanocube. Moreover, the in situ generated CSMn bonds between the MnS core and carbon shell play a significant role in improving the Na‐storage stability and reversibility of MnS@NSC, as revealed by in situ Raman and TEM. As a result, MnS@NSC exhibits a high reversible specific capacity of 594.2 mAh g−1 at a current density of 100 mA g−1 and an excellent rate performance. It also achieves a remarkable cycling stability of 329.1 mAh g−1 after 3000 charge/discharge cycles at 1 A g−1 corresponding to a low capacity attenuation rate of 0.0068% per cycle, which is superior to that of pristine MnS and most of the reported Mn‐based anode materials in SIBs.
A cube‐like core/shell composite of single MnS nanocubes encapsulated in N, S co‐doped carbon (MnS@NSC) with strong CSMn bond interactions is prepared successfully. As demonstrated by electrochemical tests and in situ studies, the MnS@NSC delivers high reversible capacity, excellent cycling stability, and rate capability as anode material in sodium‐ion batteries, which benefits from the sulfur‐bridged bonds and unique core/shell structure.
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High-quality Prussian blue crystals with a small number of vacancies and a low water content are obtained by employing Na sub(4)Fe(CN) sub(6) as the single iron-source precursor. The high-quality ...Prussian blue shows high specific capacity and remarkable cycling stability as the cathode material for Na-ion batteries because of its excellent ion storage capability and impressive structure stability.
The graphite material from exhausted Li-ion batteries (LIBs) is reused as a favorable anode for Na-ion batteries (NIBs) and K-ion batteries (KIBs) through a recycling treatment. The optimized ...electrode delivers improved electrochemical performance, such as 162 mA h g −1 in NIBs at 0.2 A g −1 and 320 mA h g −1 in KIBs at 0.05 A g −1 . In addition, the insights into Na/K-ion de-/intercalation model evolution and corresponding electrochemical analysis are conducted through in operando X-ray diffraction and a series of other characterization methods, discovering a visible transitional stage for NIBs and an irreversible initial cycle phase transformation for KIBs. In a word, we not only provide a new recycling concept for waste graphite anodes but also carry out a series of significant intercalation mechanism studies, which contribute to anode recycling and shed light on the development of graphite material for promising alternative ion batteries.
Background Deep learning (DL) algorithms are gaining extensive attention for their excellent performance in image recognition tasks. DL models can automatically make a quantitative assessment of ...complex medical image characteristics and achieve increased accuracy in diagnosis with higher efficiency. Purpose To determine the feasibility of using a DL approach to predict clinically negative axillary lymph node metastasis from US images in patients with primary breast cancer. Materials and Methods A data set of US images in patients with primary breast cancer with clinically negative axillary lymph nodes from Tongji Hospital (974 imaging studies from 2016 to 2018, 756 patients) and an independent test set from Hubei Cancer Hospital (81 imaging studies from 2018 to 2019, 78 patients) were collected. Axillary lymph node status was confirmed with pathologic examination. Three different convolutional neural networks (CNNs) of Inception V3, Inception-ResNet V2, and ResNet-101 architectures were trained on 90% of the Tongji Hospital data set and tested on the remaining 10%, as well as on the independent test set. The performance of the models was compared with that of five radiologists. The models' performance was analyzed in terms of accuracy, sensitivity, specificity, receiver operating characteristic curves, areas under the receiver operating characteristic curve (AUCs), and heat maps. Results The best-performing CNN model, Inception V3, achieved an AUC of 0.89 (95% confidence interval CI: 0.83, 0.95) in the prediction of the final clinical diagnosis of axillary lymph node metastasis in the independent test set. The model achieved 85% sensitivity (35 of 41 images; 95% CI: 70%, 94%) and 73% specificity (29 of 40 images; 95% CI: 56%, 85%), and the radiologists achieved 73% sensitivity (30 of 41 images; 95% CI: 57%, 85%;
= .17) and 63% specificity (25 of 40 images; 95% CI: 46%, 77%;
= .34). Conclusion Using US images from patients with primary breast cancer, deep learning models can effectively predict clinically negative axillary lymph node metastasis. Artificial intelligence may provide an early diagnostic strategy for lymph node metastasis in patients with breast cancer with clinically negative lymph nodes. Published under a CC BY 4.0 license.
See also the editorial by Bae in this issue.
Incorporation of N,S‐codoped nanotube‐like carbon (N,S‐NTC) can endow electrode materials with superior electrochemical properties owing to the unique nanoarchitecture and improved kinetics. Herein, ...α‐MnS nanoparticles (NPs) are in situ encapsulated into N,S‐NTC, preparing an advanced anode material (α‐MnS@N,S‐NTC) for lithium‐ion/sodium‐ion batteries (LIBs/SIBs). It is for the first time revealed that electrochemical α → β phase transition of MnS NPs during the 1st cycle effectively promotes Li‐storage properties, which is deduced by the studies of ex situ X‐ray diffraction/high‐resolution transmission electron microscopy and electrode kinetics. As a result, the optimized α‐MnS@N,S‐NTC electrode delivers a high Li‐storage capacity (1415 mA h g−1 at 50 mA g−1), excellent rate capability (430 mA h g−1 at 10 A g−1), and long‐term cycling stability (no obvious capacity decay over 5000 cycles at 1 A g−1) with retained morphology. In addition, the N,S‐NTC‐based encapsulation plays the key roles on enhancing the electrochemical properties due to its high conductivity and unique 1D nanoarchitecture with excellent protective effects to active MnS NPs. Furthermore, α‐MnS@N,S‐NTC also delivers high Na‐storage capacity (536 mA h g−1 at 50 mA g−1) without the occurrence of such α → β phase transition and excellent full‐cell performances as coupling with commercial LiFePO4 and LiNi0.6Co0.2Mn0.2O2 cathodes in LIBs as well as Na3V2(PO4)2O2F cathode in SIBs.
α‐MnS nanoparticles are in situ encapsulated into N,S‐codoped nanotube‐like carbon (α‐MnS@N,S‐NTC) as an advanced anode for Li/Na‐ion batteries. The α → β phase transition during the 1st cycle in LIBs is for the first time revealed by ex situ X‐ray diffraction and high‐resolution transmission electron microscopy studies, which improves the electrode kinetics and Li‐storage properties. α‐MnS@N,S‐NTC also exhibits superior performance in Li/Na‐ion half/full cells.
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Presently, commercialization of sodium‐ion batteries (SIBs) is still hindered by the relatively poor energy‐storage performance. In addition, low‐temperature (low‐T) Na storage is another principal ...concern for the wide application of SIBs. Unfortunately, the Na‐transfer kinetics is extremely sluggish at low‐T, as a result, there are few reports on low‐T SIBs. Here, an advanced low‐T sodium‐ion full battery (SIFB) assembled by an anode of 3D Se/graphene composite and a high‐voltage cathode (Na3V2(PO4)2O2F) is developed, exhibiting ultralong lifespan (over even 15 000 cycles, the capacity retention is still up to 86.3% at 1 A g−1), outstanding low‐T energy storage performance (e.g., all values of capacity retention are >75% after 1000 cycles at temperatures from 25 to −25 °C at 0.4 A g−1), and high‐energy/power properties. Such ultralong lifespan signifies that the developed sodium‐ion full battery can be used for longer than 60 years, if batteries charge/discharge once a day and 80% capacity retention is the standard of battery life. As a result, the present study not only promotes the practicability and commercialization of SIBs but also points out the new developing directions of next‐generation energy storage for wider range applications.
An outstanding anode material with superior low‐temperature Na‐storage performance is first prepared, and then an advanced sodium‐ion full battery is assembled and studied via coupling such anode with Na3V2(PO4)2O2F cathode. The assembled full battery exhibits ultralong cycle life, superior low‐temperature, and high‐power energy‐storage performances.
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Turbulent interfacial evolution at the Zn anode/electrolyte, leading to rampant dendrites and parasitic reactions, is responsible for low Coulombic efficiency (CE) and premature failure in Zn metal ...batteries. To address this issue, an integrated eutectic electrolyte was introduced to construct a gradient organic/inorganic hybrid SEI (GHS) layer on the Zn anode through in situ chemical reconstruction. The entanglement between the thermodynamic equilibrium of the species and the evolution of the GHS layer in a coordinated state was revealed. The GHS layer with a gradient structure and composition alleviates corrosion and passivation on the Zn anode, as well as the hydrogen evolution reaction. Additionally, the diffusion behavior of Zn2+ at the interface is optimized, allowing epitaxial deposition of Zn2+ along the (002) plane to eradicate dendrites. This results in an ultra-stable Zn anode with a substantially improved CE of 99.8% over 1200 cycles and a high cumulative plated capacity of 5.57 A h cm−2 at 5 mA cm−2. The effectiveness of this approach is demonstrated by the extremely long lifespan of 22 000 cycles of a Zn//V2O5 full cell.
Polyanion‐type phosphate materials are highly promising cathode candidates for next‐generation batteries due to their excellent structural stability during cycling; however, their poor conductivity ...has impeded their development. Isostructural and multivalent anion substitution combined with carbon coating is proposed to greatly improve the electrochemical properties of phosphate cathode in sodium‐ion batteries (SIBs). Specifically, multivalent tetrahedral SiO44− substitute for PO43− in Na3V2(PO4)3 (NVP) lattice, preparing the optimal Na3.1V2(PO4)2.9(SiO4)0.1 with high‐rate capability (delivering a high capacity of 82.5 mAh g−1 even at 20 C) and outstanding cyclic stability (≈98% capacity retention after 500 cycles at 1 C). Theoretical calculation and experimental analyses reveal that the anion‐substituted Na3.1V2(PO4)2.9(SiO4)0.1 reduces the bandgap of NVP lattice and enhanced its structural stability, Na+‐diffusion kinetics and electronic conductivity. This strategy of multivalent and isostructural anion substitution chemistry provides a new insight to develop advanced phosphate cathodes.
Na3+xV2(PO4)3−x(SiO4)x (0 ≤ x ≤ 0.15) cathode materials are prepared via substitution of the inactive PO43− sites in Na3V2(PO4)3 with isostructural SiO44− anions. The substitution effects on crystal structure, electrochemical properties, Na+‐diffusion kinetics and electronic conductivity are systematically investigated. Multivalent and isostructural anionic substitution provides a new strategy for designing polyanionic materials of sodium‐ion batteries.
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Polyanionic transition metal polyphosphate (TMPO)‐type Na3V2(PO4)2O2F (NVPO2F) is promising as cathode for large‐scale sodium‐ion batteries (SIBs) on account of its considerable capacity and highly ...stable structure. However, the redox of transition metal and phase transitions along with the (de)intercalation of Na+ lead to its slow kinetics and inferior rate performance. Herein, chlorine (Cl) is applied as a heteropical dopant to obtain Cl‐doped NVPO2F (NVPO2−xClxF) cathode material for SIBs. Density functional theory investigation reveals that Cl doping tunes the localized electronic density and structure in NVPO2F lattice, causing the electron redistribution on vanadium center and dangling anions. Hence, the NVPO2−xClxF cathode exhibits a revised redox behavior of vanadium for Na+ extraction/insertion, increases Na+ diffusion rate, as well as lowers charge transfer resistance. A Na+ storage mechanism of reversible transformations between three phases and V4+/V5+ redox couple for NVPO2−xClxF cathode is verified. The NVPO2−xClxF cathode reveals a high rate capacity of ≈63 mAh g−1 at 30C and great cycle stability over 1000 cycles at 10C. More importantly, outstanding rate property (314 Wh kg−1 at 5850 W kg−1) and cycling capability are obtained for the NVPO2−xClxF//3DC@Se full cell. This study demonstrates a brand‐new strategy to prepare advanced cathode materials for superior SIBs.
Cl‐doped Na3V2(PO4)2O2F (NVPO2−xClxF) cathode material is prepared for the first time via a facile chemical vapor replacing process. The density functional theory investigations verify that the Cl doping tunes the electronic structure and causes the electron redistribution on vanadium center/dangling anions. Therefore, a revised redox behavior of vanadium and increased Na+ diffusivity are achieved, enabling superior rate property.
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