Enhancing P2/O3 Biphasic Cathode Performance for Sodium-Ion Batteries: A Metaheuristic Approach to Multi-Element Doping Design.

Sodium-ion batteries (SIBs) have emerged as a compelling alternative to lithium-ion batteries (LIBs), exhibiting comparable electrochemical performance while capitalizing on the abundant availability of sodium resources. In SIBs, P2/O3 biphasic cathodes, despite their high energy, require furthur improvements in stability to meet current energy demands. This study introduces a systematic methodology that leverages the meta-heuristically assisted NSGA-II algorithm to optimize multi-element doping in electrode materials, aiming to transcend conventional trial-and-error methods and enhance cathode capacity by the synergistic integration of P2 and O3 phases. A comprehensive phase analysis of the meta-heuristically designed cathode material Na0.76Ni0.20Mn0.42Fe0.30Mg0.04Ti0.015Zr0.025O2 (D-NFMO) is presented, showcasing its remarkable initial reversible capacity of 175.5 mAh g-1 and exceptional long-term cyclic stability in sodium cells. The investigation of structural composition and the stabilizing mechanisms is performed through the integration of multiple characterization techniques. Remarkably, the irreversible phase transition of P2→OP4 in D-NFMO is observed to be dramatically suppressed, leading to a substantial enhancement in cycling stability. The comparison with the pristine cathode (P-NFMO) offers profound insights into the long-term electrochemical stability of D-NFMO, highlighting its potential as a high-voltage cathode material utilizing abundant earth elements in SIBs. This study opens up new possibilities for future advancements in sodium-ion battery technology.

Monolithic Interphase Enables Fast Kinetics for High-Performance Sodium-Ion Batteries at Subzero Temperature.

In spite of the competitive performance at room temperature, the development of sodium-ion batteries (SIBs) is still hindered by sluggish electrochemical reaction kinetics and unstable electrode/electrolyte interphase under subzero environments. Herein, a low-concentration electrolyte, consisting of 0.5M NaPF6 dissolving in diethylene glycol dimethyl ether solvent, is proposed for SIBs working at low temperature. Such an electrolyte generates a thin, amorphous, and homogeneous cathode/electrolyte interphase at low temperature. The interphase is monolithic and rich in organic components, reducing the limitation of Na+ migration through inorganic crystals, thereby facilitating the interfacial Na+ dynamics at low temperature. Furthermore, it effectively blocks the unfavorable side reactions between active materials and electrolytes, improving the structural stability. Consequently, Na0.7Li0.03Mg0.03Ni0.27Mn0.6Ti0.07O2//Na and hard carbon//Na cells deliver a high capacity retention of 90.8 % after 900 cycles at 1C, a capacity over 310 mAh g-1 under -30 °C, respectively, showing long-term cycling stability and great rate capability at low temperature.

Self-Optimizing Effect in Lithium Storage of GeO2 Induced by Heterointerface Regulation.

Herein, a heterostructural hexagonal@tetragonal GeO2 (HT-GeO2 ) composite has been designed based on density functional theory (DFT) calculations and synthesized via an acidic-heating route dealt with rapid cooling, where the inner hexagonal GeO2 (H-GeO2 ) phase is covered by a porous layer of tetragonal GeO2 (T-GeO2 ) owing to HF etching. Interestingly, the HT-GeO2 electrode has a self-optimizing effect in lithium storage induced by heterointerface regulation, where the porous T-GeO2 layer on the surface of HT-GeO2 can act as not only a Li+ /electron conducting layer, but also a buffer layer, while the inner H-GeO2 phase can react preferentially with Li ions owing to lower intercalation energy, which is confirmed by operando XRD measurement contributing to thorough lithiation for HT-GeO2 . Moreover, the heterointerface can enhance the pseudocapacitance effect, which can boost the Li storage and accelerate the discharge-charge process. As a result, a large capacity of 984 mAh g-1 after 500 cycles at 2 A g-1 and a capacity of 430 mAh g-1 at a high current density of 20 A g-1 are delivered. This work provides an easy and efficient way to improve the cycling stability of the GeO2 anode, and the T-GeO2 phase would be a novel anode material in energy storage devices.

High-Surface Area Mesoporous Sc2O3 with Abundant Oxygen Vacancies as New and Advanced Electrocatalyst for Electrochemical Biomass Valorization.

Scandium oxide (Sc2O3) is considered as omnipotent "Industrial Ajinomoto" and holds promise in catalytic applications. However, rarely little attention is paid to its electrochemistry. Here, the first nanocasting design of high-surface area Sc2O3 with abundant oxygen vacancies (mesoporous VO-Sc2O3) for efficient electrochemical biomass valorization is reported. In the case of the electro-oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), quantitative HMF conversion, high yield, and high faradic efficiency of FDCA via the hydroxymethylfurancarboxylic acid pathway are achieved by this advanced electrocatalyst. The beneficial effect of the VO on the electrocatalytic performance of the mesoporous VO-Sc2O3 is revealed by the enhanced adsorption of reactants and the reduced energy barrier in the electrochemical process. The concerted design, in situ and ex situ experimental studies and theoretical calculations shown in this work should shed light on the rational elaboration of advanced electrocatalysts, and contribute to the establishment of a circular carbon economy since the bio-plastic monomer and green hydrogen are efficiently synthesized.

Fundamental Understanding of the Low Initial Coulombic Efficiency in SiOx Anode for Lithium-Ion Batteries: Mechanisms and Solutions.

To meet the ever-increasing demand for high-energy lithium-ion batteries (LIBs), it is imperative to develop next-generation anode materials. Compared to conventional carbon-based anodes, Si-based materials are promising due to their high theoretical capacity and reasonable cost. SiOx, as a Si-derivative anode candidate, is particularly encouraging for its durable cycling life, the practical application of which is, however, severely hindered by low initial Coulombic efficiency (ICE) that leads to continuous lithium consumption. What is worse, low ICE also easily triggers a terrible chain reaction causing bad cycling stability. To further develop SiOx anode, researchers have obtained in-depth understandings regarding its working/failing mechanisms so as to further propose effective remedies for low ICE mitigation. In this sense, herein recent studies investigating the possible causes that fundamentally result in low ICE of SiOx, based on which a variety of solutions addressing the low ICE issue are discussed and summarized, are timely summarized. This perspective provides valuable insights into the rational design of high ICE SiOx anodes and paves the way toward industrial application of SiOx as the next generation LIB anode.

Universal Formation of Single Atoms from Molten Salt for Facilitating Selective CO2 Reduction.

Clarifying the formation mechanism of single-atom sites guides the design of emerging single-atom catalysts (SACs) and facilitates the identification of the active sites at atomic scale. Herein, a molten-salt atomization strategy is developed for synthesizing zinc (Zn) SACs with temperature universality from 400 to 1000/1100 °C and an evolved coordination from Zn-N2Cl2 to Zn-N4. The electrochemical tests and in situ attenuated total reflectance-surface-enhanced infrared absorption spectroscopy confirm that the Zn-N4 atomic sites are active for electrochemical carbon dioxide (CO2) conversion to carbon monoxide (CO). In a strongly acidic medium (0.2 m K2SO4, pH = 1), the Zn SAC formed at 1000 °C (Zn1NC) containing Zn-N4 sites enables highly selective CO2 electroreduction to CO, with nearly 100% selectivity toward CO product in a wide current density range of 100-600 mA cm-2. During a 50 h continuous electrolysis at the industrial current density of 200 mA cm-2, Zn1NC achieves Faradaic efficiencies greater than 95% for CO product. The work presents a temperature-universal formation of single-atom sites, which provides a novel platform for unraveling the active sites in Zn SACs for CO2 electroreduction and extends the synthesis of SACs with controllable coordination sites.

Atomically Dispersed Manganese on Carbon Substrate for Aqueous and Aprotic CO2 Electrochemical Reduction.

CO2 utilization and conversion are of great importance in alleviating the rising CO2 concentration in the atmosphere. Here, a single-atom catalyst (SAC) is reported for electrochemical CO2 utilization in both aqueous and aprotic electrolytes. Specifically, atomically dispersed Mn-N4 sites are embedded in bowl-like mesoporous carbon particles with the functionalization of epoxy groups in the second coordination spheres. Theoretical calculations suggest that the epoxy groups near the Mn-N4 site adjust the electronic structure of the catalyst with reduced reaction energy barriers for the electrocatalytic reduction of CO2 to CO. The resultant Mn-single-atom carbon with N and O doped catalyst (MCs-(N,O)) exhibits extraordinary electrocatalytic performance with a high CO faradaic efficiency of 94.5%, a high CO current density of 13.7 mA cm-2 , and a low overpotential of 0.44 V in the aqueous environment. Meanwhile, as a cathode catalyst for aprotic Li-CO2 batteries, the MCs-(N,O) with well-regulated active sites and unique mesoporous bowl-like morphology optimizes the nucleation behavior of discharge products. MCs-(N,O)-based batteries deliver a low overpotential and excellent cyclic stability of 1000 h. The findings in this work provide a new avenue to design and fabricate SACs for various electrochemical CO2 utilization systems.

High stability and high performance nitrogen doped carbon containers for lithium-ion batteries.

For a long time, carbon has been an ideal material for various electrochemical energy storage devices and a key component in electrochemical energy storage systems due to its advantages of rich surface states, easy tenability, and good chemical stability. Stable and high-performance carbon materials can support future applications of high specific energy electrodes. Herein and for the first time, we have designed nitrogen-doped carbon hollow containers using oleylamine-coating TiO2 mesocrystals as a precursor with a high specific surface area of 1231 m2 g-1. When applied as an anode for lithium-ion storage, a reversible capacity of 774.5 mA h g-1 is obtained at a rate of 0.5 A g-1 after 200 cycles. Meanwhile, at an even higher rate of 2 A g-1, a capacity of 721.1 mA h g-1 is still achieved after 500 cycles. Moreover, the carbon containers remain structurally intact after a series of cycles. This may be attributed to the nitrogen atoms doped on the carbon surface that can absorb multiple lithium ions and enhance the structural stability. These results provide technical support for the development of high specific energy electrode materials.

Upregulation of Versican Associated with Tumor Progression, Metastasis, and Poor Prognosis in Bladder Carcinoma.

OBJECTIVE: This work analyzes the role of versican (VCAN) on bladder cancer (BLCA). Versican (VCAN) is a chondroitin sulfate proteoglycan which is important for tumorigenesis and the development of cancer. However, the expression of VCAN on human bladder cancer (BLCA) has been rarely reported. METHODS: The clinical significance of VCAN in BLCA has been determined by our bioinformatics tools. Then, we performed immunohistochemical staining (IHC) and analyzed the correlation between VCAN expression and clinicopathological features. RESULTS: The bioinformatics results reveal that a high VCAN mRNA level was significantly associated with stage, histological subtype, molecular subtype, and metastasis in BLCA. Furthermore, IHC reveals that expression of VCAN was significantly correlated with the number of tumors, invasion depth, lymph node metastasis, distant metastasis, and histological grade. Kaplan-Meier survival analysis reveals that patients with a high expression of VCAN have poor prognosis than those patients with a low expression of VCAN. According to our result from the bioinformatics database, the mechanism of VCAN in BLCA revealed that VCAN was related to FBN1 and genes of the ECM remodeling pathway (MMP1, MMP2). CONCLUSION: VCAN expression might be included in the process of carcinogenesis and prognosis. Hence, VCAN could be a reliable biomarker of the clinical prognosis on BLCA.

Bismuth-Antimony Alloy Nanoparticle@Porous Carbon Nanosheet Composite Anode for High-Performance Potassium-Ion Batteries.

Antimony (Sb)-based anode materials have recently aroused great attention in potassium-ion batteries (KIBs), because of their high theoretical capacities and suitable potassium inserting potentials. Nevertheless, because of large volumetric expansion and severe pulverization during potassiation/depotassiation, the performance of Sb-based anode materials is poor in KIBs. Herein, a composite nanosheet with bismuth-antimony alloy nanoparticles embedded in a porous carbon matrix (BiSb@C) is fabricated by a facile freeze-drying and pyrolysis method. The introduction of carbon and bismuth effectively suppress the stress/strain originated from the volume change during charge/discharge process. Excellent electrochemical performance is achieved as a KIB anode, which delivers a high reversible capacity of 320 mA h g-1 after 600 cycles at 500 mA g-1. In addition, full KIBs by coupling with Prussian Blue cathode deliver a high capacity of 396 mA h g-1 and maintain 360 mA h g-1 after 70 cycles. Importantly, the operando X-ray diffraction investigation reveals a reversible potassiation/depotassiation reaction mechanism of (Bi,Sb) ↔ K(Bi,Sb) ↔ K3(Bi,Sb) for the BiSb@C composite. Our findings not only propose a reasonable design of high-performance alloy-based anodes in KIBs but also promote the practical use of KIBs in large-scale energy storage.