ABSTRACT
Searching for high energy-density electrode materials for sodium ion batteries has revealed Na-deficient intercalation compounds with lattice oxygen redox as promising high-capacity cathodes. However, anionic redox reactions commonly encountered poor electrochemical reversibility and unfavorable structural transformations during dynamic (de)sodiation processes. To address this issue, we employed lithium orbital hybridization chemistry to create Na-O-Li configuration in a prototype P2-layered Na43/60Li1/20Mg7/60Cu1/6Mn2/3O2 (P2-NaLMCM') cathode material. That Li+ ions, having low electronegativity, reside in the transition metal slabs serves to stimulate unhybridized O 2p orbitals to facilitate the stable capacity contribution of oxygen redox at high state of charge. The prismatic-type structure evolving to an intergrowth structure of the Z phase at high charging state could be simultaneously alleviated by reducing the electrostatic repulsion of O-O layers. As a consequence, P2-NaLMCM' delivers a high specific capacity of 183.8 mAh g-1 at 0.05 C and good cycling stability with a capacity retention of 80.2% over 200 cycles within the voltage range of 2.0-4.5 V. Our findings provide new insights into both tailoring oxygen redox chemistry and stabilizing dynamic structural evolution for high-energy battery cathode materials.
ABSTRACT
Viral communities exist in a variety of ecosystems and play significant roles in mediating biogeochemical processes, whereas viruses inhabiting strongly alkaline geochemical systems remain underexplored. In this study, the viral diversity, potential functionalities, and virus-host interactions in a strongly alkaline environment (pH = 10.4-12.4) exposed to the leachates derived from the serpentinization-like reactions of smelting slags were investigated. The viral populations (e.g., Herelleviridae, Queuovirinae, and Inoviridae) were closely associated with the dominating prokaryotic hosts (e.g., Meiothermus, Trueperaceae, and Serpentinomonas) in this ultrabasic environment. Auxiliary metabolic genes (AMGs) suggested that viruses may enhance hosts' fitness by facilitating cofactor biosynthesis, hydrogen metabolism, and carbon cycling. To evaluate the activity of synthesis of essential cofactor vitamin B9 by the viruses, a viral folA (vfolA) gene encoding dihydrofolate reductase (DHFR) was introduced into a thymidine-auxotrophic strain Escherichia coli MG1655 ΔfolA mutant, which restored the growth of the latter in the absence of thymidine. Notably, the homologs of the validated vDHFR were globally distributed in the viromes across various ecosystems. The present study sheds new light on the unique viral communities in hyperalkaline ecosystems and their potential beneficial impacts on the coexisting microbial consortia by supplying essential cofactors. IMPORTANCE: This study presents a comprehensive investigation into the diversity, potential functionalities, and virus-microbe interactions in an artificially induced strongly alkaline environment. Functional validation of the detected viral folA genes encoding dihydrofolate reductase substantiated the synthesis of essential cofactors by viruses, which may be ubiquitous, considering the broad distribution of the viral genes associated with folate cycling.
ABSTRACT
2D compounds exfoliated from weakly bonded bulk materials with van der Waals (vdW) interaction are easily accessible. However, the strong internal ionic/covalent bonding of most inorganic crystal frameworks greatly hinders 2D material exfoliation. Herein, we first proposed a radical/strain-synergistic strategy to exfoliate non-vdW interacting pseudo-layered phosphate framework. Specifically, hydroxyl radicals (â OH) distort the covalent bond irreversibly, meanwhile, H2O molecules as solvents, further accelerating interlayered ionic bond breakage but mechanical expansion. The innovative 2D laminar NASICON-type Na3V2(PO4)2O2F crystal, exfoliated by â OH/H2O synergistic strategy, exhibits enhanced sodium-ion storage capacity, high-rate performance (85.7â mAh g-1 at 20â C), cyclic life (2300 cycles), and ion migration rates, compared with the bulk framework. Importantly, this chemical/physical dual driving technique realized the effective exfoliation for strongly coupled pseudo-layered frameworks, which accelerates 2D functional material development.
ABSTRACT
Interlayer intercalation engineering shows great feasibility to improve the structure stability of the layered oxides. Although high Zn-storage capability has been attained based on the pillar effect of multifarious intercalants, an in-depth understanding the synergistic effect of intercalated multiple metal ions is still in deficiency. Herein, alkali metal ion K+, alkaline earth metal ion Mg2+ and trivalent metal ion Al3+ are introduced into the VO interlayer of V2O5. Due to the different electronegativity and hydrated ion radius of K+, Mg2+ and Al3+, adjusting the relative proportions of these metal ions can achieve an appropriate interlayer spacing, stable layer structure and regular morphology, which facilitates the transport kinetics of Zn2+. Under the synergistic effect of pre-intercalated multi-metal ion, the optimal tri-metal ion intercalated hydrated V2O5 cathode exhibits a high specific capacity of 382.4 mAh g-1 at 0.5 A g-1, and long-term cycling stability with capacity retention of 86 % after 2000 cycles at the high current density of 10 A g-1. Ex-situ and kinetic characterizations reveal the fast charge transfer and reversible Zn2+ intercalation mechanism. The multi-ion engineering strategy provides an effective way to design desirable layered cathode materials for aqueous zinc-ion batteries.
ABSTRACT
Due to the rapid increase in the number of spent lithium-ion batteries, there has been a growing interest in the recovery of degraded graphite. In this work, a rapid thermal shock (RTS) strategy is proposed to regenerate spent graphite for use in lithium-ion batteries. The results of structural and morphological characterization demonstrate that the graphite is well regenerated by the RTS process. Additionally, an amorphous carbon layer forms and coats onto the surface of the graphite, contributing to excellent rate performance. The regenerated graphite (RG-1000) displays excellent rate performance, with capacities of 413 mAh g-1 at 50 mA g-1 and 102.1 mAh g-1 at 1000 mA g-1, respectively. Furthermore, it demonstrates long-term cycle stability, maintaining a capacity of 80 mAh g-1 at 1000 mA g-1 with a capacity retention of 78.4 % after 600 cycles. This RTS method enables rapid and efficient regeneration of spent graphite anodes for lithium-ion batteries, providing a facile and environmentally friendly strategy for their direct regeneration.
ABSTRACT
The stable phase transformation during electrochemical progress drives extensive research on vanadium-based polyanions in sodium-ion batteries (SIBs), especially Na3V2(PO4)3 (NVP). And the electron transfer between V3+/4+ redox couple in NVP could be generally achieved, owing to the confined crystal variation during battery service. However, the more favorable V4+/5+ redox couple is still in hard-to-access situation due to the high barrier and further brings about the corresponding inefficiency in energy densities. In this work, the multilevel redox in NVP frame (MLNP) alters reaction pathway to undergo homeostatic solid solution process and breaks the high barrier of V4+/5+ at high voltage, taking by progressive transition metal (V, Fe, Ti, and Cr) redox couple. The diversified reaction paths across diffusion barriers could be realized by distinctive release/uptake of inactive Na1 site, confirmed by the calculations of density functional theory. Thereby its volume change is merely 1.73% during the multielectron-transfer process (≈2.77 electrons). MLNP cathode could achieve an impressive energy density of 440 Wh kg-1, driving the leading development of MLNP among other NASICON structure SIBs. The integration of multiple redox couples with low strain modulates the reaction pathway effectively and will open a new avenue for fabricating high-performance cathodes in SIBs.
ABSTRACT
After application in electric vehicles, spent LiFePO4 (LFP) batteries are typically decommissioned. Traditional recycling methods face economic and environmental constraints. Therefore, direct regeneration has emerged as a promising alternative. However, irreversible phase changes can significantly hinder the efficiency of the regeneration process owing to structural degradation. Moreover, improper storage and treatment practices can lead to metamorphism, further complicating the regeneration process. In this study, a sustainable recovery method is proposed for the electrochemical repair of LFP batteries. A ligand-chain Zn-complex (ZnDEA) is utilized as a structural regulator, with its âNHâ group alternatingly facilitating the binding of preferential transition metal ions (Fe3+ during charging and Zn2+ during discharging). This dynamic coordination ability helps to modulate volume changes within the recovered LFP framework. Consequently, the recovered LFP framework can store more Li-ions, enhance phase transition reversibility between LFP and FePO4 (FP), modify the initial Coulombic efficiency, and reduce polarization voltage differences. The recovered LFP cells exhibit excellent capacity retention of 96.30% after 1500 cycles at 2 C. The ligand chain repair mechanism promotes structural evolution to facilitate ion migration, providing valuable insights into the targeted ion compensation for environmentally friendly recycling in practical applications.
ABSTRACT
Since sodium-ion batteries (SIBs) have become increasingly commercialized in recent years, Na3V2(PO4)2O2F (NVPOF) offers promising economic potential as a cathode for SIBs because of its high operating voltage and energy density. According to reports, NVPOF performs poorly in normal commercial poly(vinylidene fluoride) (PVDF) binder systems and performs best in combination with aqueous binder. Although in line with the concept of green and sustainable development for future electrode preparation, aqueous binders are challenging to achieve high active material loadings at the electrode level, and their relatively high surface tension tends to cause the active material on the electrode sheet to crack or even peel off from the collector. Herein, a cross-linkable and easily commercial hybrid binder constructed by intermolecular hydrogen bonding (named HPP) has been developed and utilized in an NVPOF system, which enables the generation of a stable cathode electrolyte interphase on the surface of active materials. According to theoretical simulations, the HPP binder enhances electronic/ionic conductivity, which greatly lowers the energy barrier for Na+ migration. Additionally, the strong hydrogen-bond interactions between the HPP binder and NVPOF effectively prevent electrolyte corrosion and transition-metal dissolution, lessen the lattice volume effect, and ensure structural stability during cycling. The HPP-based NVPOF offers considerably improved rate capability and cycling performance, benefiting from these benefits. This comprehensive binder can be extended to the development of next-generation energy storage technologies with superior performance.
ABSTRACT
Flexible quasi-solid-state sodium ion batteries featuring their low-cost, high safety and excellent mechanical strength have attracted widespread interest in the field of wearable electronic devices. However, the development of such batteries faces great challenges including the construction of interfacial compatible flexible electrode materials and addressing the high safety demands of electrolyte. Here selenium-vacancies regulated bimetallic selenide heterojunctions anchored on waste cotton cloth-derived flexible carbon cloth (FCC) with robust interfacial C-Se-Co/Fe chemical bonds as a flexible anode material (CCFSF) is proposed by ultrafast microwave pyrolysis method. Rich selenium vacancies and CoSe2 /FeSe2-x heterostructures are synchronously formed that can significantly improve ionic and electronic diffusion kinetics. Additionally, a uniform carbon layer coating on the surface of Se-deficient heterostructures endows it with outstanding structural stability. The flexible cathode (PB@FCC) is also fabricated by directly growing Prussian blue nanoparticles on the FCC. Furthermore, an advanced flexible quasi-solid-state Na-ion pouch cell is assembled by coupling CCFSF anode, PB@FCC cathode with P(VDF-HFP)-based gel polymer electrolyte. The full cell not only demonstrates excellent energy storage performance but also robust mechanical flexibility and safety. The present work offers an effective avenue to achieve high safety flexible energy storage device, promoting the development of flexible wearable electronic devices.
ABSTRACT
Based on the favorable ionic conductivity and structural stability, sodium superionic conductor (NASICON) materials especially utilizing multivalent redox reaction of vanadium are one of the most promising cathodes in sodium-ion batteries (SIBs). To further boost their application in large-scale energy storage production, a rational strategy is to tailor vanadium with earth-abundant and cheap elements (such as Fe, Mn), reducing the cost and toxicity of vanadium-based NASICON materials. Here, the Na3.05 V1.03 Fe0.97 (PO4 )3 (NVFP) is synthesized with highly conductive Ketjen Black (KB) by ball-milling assisted sol-gel method. The pearl-like KB branch chains encircle the NVFP (p-NVFP), the segregated particles possess promoted overall conductivity, balanced charge, and modulated crystal structure during electrochemical progress. The p-NVFP obtains significantly enhanced ion diffusion ability and low volume change (2.99%). Meanwhile, it delivers a durable cycling performance (87.7% capacity retention over 5000 cycles at 5 C) in half cells. Surprisingly, the full cells of p-NVFP reveal a remarkable capability of 84.9 mAh g-1 at 20 C with good cycling performance (capacity decay rate is 0.016% per cycle at 2 C). The structure modulation of the p-NVFP provides a rational design on the superiority of others to be put into practice.
ABSTRACT
With the rapid development of sodium-ion batteries (SIBs), it is urgent to exploit the cathode materials with good rate capability, attractive high energy density and considerable long cycle performance. Na3V2(PO4)3(NVP), as a NASICON-type electrode material, is one of the cathode materials with great potential for application because of its good thermal stability and stable. However, NVP has the inherent problem of low electronic conductivity, and various strategies are proposed to improve it, moreover, nanotechnology or nanostructure are involved in these strategies, the construction of nanostructured active particles and nanocomposites with conductive carbon networks have been shown to be effective in improving the electrical conductivity of NVP. Herein, we review the research progress of NVP performance improvement strategies from the perspective of nanostructures and classifies the prepared nanomaterials according to their different nano-dimension. In addition, NVP nanocomposites are reviewed in terms of both preparation methods and promotion effects, and examples of NVP nanocomposites at different nano-dimension are given. Finally, some personal views are presented to provide reasonable guidance for the research and design of high-performance polyanionic cathode materials of SIBs.
ABSTRACT
The γ-proteobacterium Shewanella oneidensis MR-1 reduces iodate to iodide extracellularly. Both dmsEFAB and mtrCAB gene clusters are involved in extracellular reduction of iodate by S. oneidensis MR-1. DmsEFAB reduces iodate to hypoiodous acid and hydrogen peroxide (H2O2). Subsequently, H2O2 is reduced by MtrCAB to facilitate DmsEFAB-mediated extracellular reduction of iodate. To investigate the distribution of bacteria with the capability for extracellular reduction of iodate, bacterial genomes were systematically searched for both dmsEFAB and mtrCAB gene clusters. The dmsEFAB and mtrCAB gene clusters were found in three Ferrimonas and 26 Shewanella species. Coexistence of both dmsEFAB and mtrCAB gene clusters in these bacteria suggests their potentials for extracellular reduction of iodate. Further analyses demonstrated that these bacteria were isolated from a variety of ecosystems, including the lakes, rivers, and subsurface rocks in East and Southeast Asia, North Africa, and North America. Importantly, most of the bacteria with both dmsEFAB and mtrCAB gene clusters were found in different marine environments, which ranged from the Arctic Ocean to Antarctic coastal marine environments as well as from the Atlantic Ocean to the Indian and Pacific Oceans. Widespread distribution of the bacteria with capability for extracellular reduction of iodate around the world suggests their significant importance in global biogeochemical cycling of iodine. The genetic organization of dmsEFAB and mtrCAB gene clusters also varied substantially. The identified mtrCAB gene clusters often contained additional genes for multiheme c-type cytochromes. The numbers of dmsEFAB gene cluster detected in a given bacterial genome ranged from one to six. In latter, duplications of dmsEFAB gene clusters occurred. These results suggest different paths for these bacteria to acquire their capability for extracellular reduction of iodate.
ABSTRACT
Although graphite anodes operated with representative de/intercalation patterns at low potentials are considered highly desirable for K-ion batteries, the severe capacity fading caused by consecutive reduction reactions on the aggressively reactive surface is inevitable given the scarcity of effective protecting layers. Herein, by introducing a flame-retardant localized high-concentration electrolyte with retentive solvation configuration and relatively weakened anion-coordination and non-solvating fluorinated ether, the rational solid electrolyte interphase characterized by well-balanced inorganic/organic components is tailored in situ. This effectively prevented solvents from excessively decomposing and simultaneously improved the resistance against K-ion transport. Consequently, the graphite anode retained a prolonged cycling capability of up to 1400cycles (245 mA h g-1, remaining above 12mon) with an excellent capacity retention of as high as 92.4%. This is superior to those of conventional and high-concentration electrolytes. Thus, the optimized electrolyte with moderate salt concentration is perfectly compatible with graphite, providing a potential application prospect for K-storage evolution.
ABSTRACT
To investigate their roles in extracellular reduction of iodate (IO3 - ) with lactate as an electron donor, the gene clusters of dmsEFAB, mtrCAB, mtrDEF and so4360-4357 in Shewanella oneidensis MR-1 were systematically deleted. Deletions of dmsEFAB and/or mtrCAB gene clusters diminished the bacterial ability to reduce IO3 - . Furthermore, DmsEFAB and MtrCAB worked collaboratively to reduce IO3 - of which DmsEFAB played a more dominant role than MtrCAB. MtrCAB was involved in detoxifying the reaction intermediate hydrogen peroxide (H2 O2 ). The reaction intermediate hypoiodous acid (HIO) was also found to inhibit microbial IO3 - reduction. SO4360-4357 and MtrDEF, however, were not involved in IO3 - reduction. Collectively, these results suggest a novel mechanism of extracellular reduction of IO3 - at molecular level, in which DmsEFAB reduces IO3 - to HIO and H2 O2 . The latter is further reduced to H2 O by MtrCAB to facilitate the DmsEFAB-mediated IO3 - reduction. The extracellular electron transfer pathway of S. oneidensis MR-1 is believed to mediate electron transfer from bacterial cytoplasmic membrane, across the cell envelope to the DmsEFAB and MtrCAB on the bacterial outer membrane.
Subject(s)
Iodates , Shewanella , Iodates/metabolism , Lactic Acid/metabolism , Electrons , Bacterial Proteins/metabolism , Shewanella/genetics , Shewanella/metabolism , Electron Transport , Oxidation-ReductionABSTRACT
In recent years, with the vigorous development and gradual deployment of new energy vehicles, more attention has been paid to the research on lithium-ion batteries (LIBs). Compared with the booming LIBs, lithium primary batteries (LPBs) own superiority in specific energy and self-discharge rate and are usually applied in special fields such as medical implantation, aerospace, and military. Widespread application in special fields also means more stringent requirements for LPBs in terms of energy density, working temperature range and shelf life. Therefore, how to obtain LPBs with high energy density, wide operational temperature range and long storage life is of great importance in future development. In view of the above, this paper reviews the latest research on LPBs in cathode, anode and electrolyte over the years, and puts forward relevant insights for LPBs, along with the intention to explore avenues for the design of LPBs components in the coming decades and promote further development in this field.
ABSTRACT
All-solid-state hybrid-ion batteries exhibiting a synergistic Na+/Li+ de/intercalation mechanism were designed and assembled, by using modified PEO-based solid polymer electrolyte, Na2V2(PO4)2O2F cathode, and Li metal anode. The batteries exhibited a high average working voltage of 3.88 V, and an energy density of 432.37 W h kg-1, providing a new avenue for the development of high-safety and low-cost secondary batteries.
ABSTRACT
Impossible voltage plateau regulation for the cathode materials with fixed active elemental center is a pressing issue hindering the development of Na-superionic-conductor (NASICON)-type Na3 V2 (PO4 )2 F3 (NVPF) cathodes in sodium-ion batteries (SIBs). Herein, a high-entropy substitution strategy, to alter the detailed crystal structure of NVPF without changing the central active V atom, is pioneeringly utilized, achieving simultaneous electronic conductivity enhancement and diffusion barrier reduction for Na+ , according to theoretical calculations. The as-prepared carbon-free high-entropy Na3 V1.9 (Ca,Mg,Al,Cr,Mn)0.1 (PO4 )2 F3 (HE-NVPF) cathode can deliver higher mean voltage of 3.81 V and more advantageous energy density up to 445.5 Wh kg-1 , which is attributed by the diverse transition-metal elemental substitution in high-entropy crystalline. More importantly, high-entropy introduction can help realize disordered rearrangement of Na+ at Na(2) active sites, thereby to refrain from unfavorable discharging behaviors at low-voltage region, further lifting up the mean working voltage to realize a full Na-ion storage at the high voltage plateau. Coupling with a hard carbon (HC) anode, HE-NVPF//HC SIB full cells can deliver high specific energy density of 326.8 Wh kg-1 at 5 C with the power density of 2178.9 W kg-1 . This route means the unlikely potential regulation in NASICON-type crystal with unchangeable active center becomes possible, inspiring new ideas on elevating the mean working voltage for SIB cathodes.
ABSTRACT
Although ether-based electrolytes have been extensively applied in anode evaluation of batteries, anodic instability arising from solvent oxidability is always a tremendous obstacle to matching with high-voltage cathodes. Herein, by rational design for solvation configuration, the fully coordinated ether-based electrolyte with strong resistance against oxidation is reported, which remains anodically stable with high-voltage Na3 V2 (PO4 )2 O2 F (NVPF) cathode under 4.5â V (versus Na+ /Na) protected by an effective interphase. The assembled graphite//NVPF full cells display superior rate performance and unprecedented cycling stability. Beyond that, the constructed full cells coupling the high-voltage NVPF cathode with hard carbon anode exhibit outstanding electrochemical performances in terms of high average output voltage up to 3.72â V, long-term cycle life (such as 95 % capacity retention after 700 cycles) and high energy density (247â Wh kg-1 ). In short, the optimized ether-based electrolyte enriches systematic options, the ability to maintain oxidative stability and compatibility with various anodes, exhibiting attractive prospects for application.