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Abstract: Electrochemically active carbon (EAC), Gallium (III) oxide (Ga2O3) and Bismuth (III) oxide (Bi2O3) are used as the negative additives of valve-regulated lead-acid (VRLA) batteries to prolong the cycle life of VRLA batteries under high-rate partial-state-of-charge (HRPSoC) conditions, and their effects on the cycle life of VRLA batteries are investigated. It is found that the addition of EAC in negative active material can restrain the sulfation of the negative plates and prolong the cycle performance of VRLA batteries under HRPSoC conditions. It is also observed that the addition of Ga2O3 or Bi2O3 in EAC can effectively increase the overpotential of hydrogen evolution on EAC electrodes, and decrease the evolution rate of hydrogen. An appropriate addition amount of Ga2O3 or Bi2O3 in the negative plates of VRLA batteries can decrease the cut-off charging voltage, increase the cut-off discharging voltage, and prolong the cycle life of VRLA batteries under HRPSoC conditions. The battery added with 0.5% EAC and 0.01% Ga2O3 in negative active material shows a lowest cut-off charging voltage and a highest cut-off discharging voltage under HRPSoC conditions, and its' cycle life reaches about 8100 cycles which is at least three times longer than that without Ga2O3. [Copyright &y& Elsevier]

Lithium-sulfur batteries engage widespread attention due to their high theoretical capacity in recent years. However, the shuttle effect and some other issues are not thoroughly solved at present. Here, VO 2 nanotubes with relatively higher redox potential (than sulfur) are in situ compounded with graphene (G) for constructing an effective VO 2 /G binary sulfur host. In such a binary host, VO 2 nanotubes are able to chemically adsorb soluble lithium polysulfides (LiPSs) and optimize their electrochemical conversion kinetics, thereby, inhibiting the shuttle effect of LiPSs. In addition, the presence of graphene can be capable of improving the electronic conductivity of the cathode material and reducing the polarization of the whole electrode. Impressively, the final fabricated VO 2 /G/S electrode delivers large specific capacity, good rate performance and stable cycling performance, which holds great potential for different applications. One-step hydrothermal method has been used to synthesis VO 2 nanotubes grown on graphene (VO 2 /G), in which, VO 2 nanotubes with strong chemical polarity and high electrochemical redox potential play the key roles for chemically adsorption of soluble lithium polysulfide and accelerating the conversion process between long-chain lithium polysulfide and short-chain Li 2 S 2 /Li 2 S, and thus effectively inhibit the "shuttle effect" during charge and discharge process. Image 1 [ABSTRACT FROM AUTHOR]

Lithium metal is considered to be one of the most promising anode materials for next-generation energy storage systems. However, low Coulombic efficiency and dendrite growth during cycling limit the practical applications of lithium metal. In this work, a non-combustible inorganic electrolyte-LiAlCl 4 · 3SO 2 is modified with LiF additive to achieve a more stable lithium metal anode. By adding 0.3 wt % LiF to LiAlCl 4 · 3SO 2 , the ionic conductivity and lithium ion transference number of LiAlCl 4 · 3SO 2 are increased, and lithium ion migration through the solid electrolyte interface (SEI) film of lithium metal anode is easier. Thus, a more stable lithium metal anode is achieved. Therefore, at 2.0 mA cm−2 and 2.0 mAh·cm−2, Li|Cu cells with LiAlCl 4 · 3SO 2 containing 0.3 wt % LiF can provide a stable cycling for 310 h with an average Coulombic efficiency up to 97.0%. Moreover, the addition of 0.3 wt % LiF in LiAlCl 4 · 3SO 2 can also improve the electrochemical performance of Li-SO 2 full-cell. With an areal capacity of 2 mAh·cm−2, Li-SO 2 cell with LiAlCl 4 · 3SO 2 containing 0.3 wt % LiF can deliver ∼900 mAh·g (carbon)−1 at a discharge current densities of 0.5 A g (carbon)−1. Therefore, we believe that a simple and effective solution is provided in this work to improve the stability of lithium metal anode with LiAlCl 4 · 3SO 2 inorganic electrolyte. By adding 0.3 wt % LiF to LiAlCl 4 · 3SO 2 , the ionic conductivity and lithium ion transference number of LiAlCl 4 · 3SO 2 were increased, and lithium ion migration through the SEI film of lithium metal anode was easier. As a result, a more stable lithium metal surface and more excellent electrochemical performance of the lithium metal batteries (Li|Cu and Li-SO 2 cells) can be achieved. Image 1 • Adding LiF to LiAlCl 4 ·3SO 2 (IE) is developed for improving the stability of lithium metal anode. • 0.3 wt % LiF in IE could make lithium ion migration through the SEI film of lithium metal anode easier. • Li-SO 2 cell with 0.3% LiF-IE can deliver ∼870 mAh·g (carbon)−1 at 0.5 A g (carbon)−1. [ABSTRACT FROM AUTHOR]

Many modifications of matrixes and hosts (e.g., Cu foil or Cu foam) have been used to solve the dendrite problem of Li metal anodes, but most of them neglect the effect of the properties for the current collector itself. In this work, the performance of Cu foam as Li deposition scaffold with different sizes (e.g., thickness and pore density) were compared. By contrast, the blank Cu foam with 1.6 mm thickness and 100 pores per liner inch has been demonstrated with the best performance (96.1% of Coulombic efficiency after 130 cycles at 5 mA/cm2 for 1 mAh/cm2 of Li), which is selected as the optimized sample for further modification to solve its dendrite problems. A facile water bath method was used to treat Cu foam for in situ growth of the CuO submicro-sheets on the three-dimensional (3D) skeletons with good electronic contact between the conductive (Cu foam) and lithiophilic (CuO) component. The 3D hierarchical structure not only ensures good lithophilic properties to induce uniform Li nucleation and deposition, but also reduces the real current density, which is beneficial to reduce the polarization of Li deposition. The electrochemical test results demonstrate the high Coulombic efficiencies of 96.5% (135 cycles), 97.5% (230 cycles) and 98.6% (450 cycles) with the current densities of 10 mA/cm2, 5 mA/cm2 and 1 mA/cm2, respectively. Moreover, the presented in-situ growth method is simple, cost-effective, and suitable for large-scale production. In addition, we pointed out the deficiencies of the proposed substrate, proposing that other strategies such as electrolyte modification and SEI modification are still needed to work together to further improve the overall performance of Li metal anode. A 3D hierarchical structured Cu foam in situ growth with CuO submicro-sheets was constructed and used as substrate for uniform Li deposition, which exhibited high Coulombic efficiency and superior electrochemical performance for both symmetric and full cells. Image 1 • A 3D hierarchical structured lithiophilic CuO submicro-sheets was constructed. • Uniform Li deposition and Li stripping was obtained on the CuO substrate. • High Coulombic efficiency, high current density and long lifespan were achieved. • The full cell exhibited improved rate performance and cyclic stability. • The deficiencies of the proposed CuO substrate were discussed. [ABSTRACT FROM AUTHOR]

Rechargeable zinc batteries (RZBs) are hindered by two primary challenges: instability of Zn anode and deterioration of the cathode structure in traditional aqueous electrolytes, largely attributable to the decomposition of active H 2 O. Here, we design and synthesize a non-flammable water-in-dimethyl sulfoxide electrolyte to address these issues. X-ray absorption spectroscopy, in situ techniques and computational simulations demonstrate that the activity of H 2 O in this electrolyte is extremely compressed, which not only suppresses the side reactions and increases the reversibility of Zn anode, but also diminishes the cathode dissolution and proton intercalation. The hybrid solid-electrolyte interface (SEI), formed in situ, helps Zn-Zn symmetric cell a prolonged lifespan exceeding 10000 h at 0.5 mA cm -2 and 600 h at a 60 % discharge depth. The versatility of this electrolyte endows the Zn-VO 2 full batteries ultra-stable cycling performance. This work provides insights into electrolyte structure-property relationships, and facilitates the design of high-performance RZBs., (© 2025 Wiley-VCH GmbH.)

Heterogeneous element doping in amorphous carbon films can reduce residual stresses and improve plastic deformation. Nevertheless, the effects of dopant content and size on the metastable transition mechanism between sp 2 -C and sp 3 -C atoms during the deformation process are unclear and difficult to be in situ observed and researched, experimentally. In this work, the mechanical properties and the structural evolution during the nanoindentation of amorphous CoCrFeNi sphere-doped carbon heterostructured films with different radii were simulated. The results indicate that the hardness H and elastic modulus E of the films decreased with the increase of the dopant addition. H decreases from 50.69 to 28.94 GPa, and E decreases from 664.39 to 448.62 GPa. The decrease in the elastic recovery and the enlargement of the shear transition zones indicate that the presence of the amorphous CoCrFeNi dopant can significantly improve the plastic deformation capacity of the films. During the nanoindentation process, the spherical dopants reduce the stress and shear strain of the regions under the indenter in a-C films. The reduction of compressive and shear stresses in the film can inhibit the C atom metastable transition from sp 2 -C to sp 3 -C. This can provide a theoretical basis for the development and design of heavy-load and high-deformation-rate a-C films.

Aqueous zinc-ion batteries (AZIBs) have garnered considerable interest as potential solutions for large-scale energy storage systems, owing to their cost-effectiveness and high safety. Nonetheless, the development of AZIBs is hindered by significant challenges associated with dendrite growth and side reactions on Zn anodes. Here, a bio-based separator derived from cellulose was developed for the dendrite-free anode in AZIBs. In addition, the separator is notable for its ultra-low cost and biodegradability in contrast to the commonly used commercial glass fiber (GF) separators. The mechanical strength of the separator is enhanced by the cross-linking of hydrogen bonds, effectively inhibiting dendrite growth. The zinc-philic groups facilitate better binding to Zn 2+ , resulting in uniform nucleation and deposition. The hydrophilic groups aid in trapping water molecules, thereby preventing side reactions of the electrolyte. The Zn||Zn symmetric cell with this separator can sustain a long cycle life for over 800 h, indicating stable Zn 2 + plating and stripping with suppressed dendrite growth. Concurrently, the assembled Zn||VO 2 full batteries exhibited a capacity retention rate of 61.87% after 1,000 cycles at 1 A g -1 with an initial capacity of 140 mAh g -1 . This work highlights a stable, economical, and eco-friendly approach to the design of bio-based separators in AZIBs for sustainable energy storage systems., Competing Interests: The authors declare no competing interests., (© 2024 Published by Elsevier Inc.)

Cold metal transfer arc additive manufacturing technique was used to produce 5356 aluminum alloy by adding refining agents to solve the problems of coarse grains and poor performance. Metallic powders (Ti, TiH, and Ti+B 4 C) were used to refine the grain size and promote the mechanical properties of the alloy. The effects of refining agents on the microstructure and mechanical properties of straight wall samples (SWSs) were studied. Samples with Ti+B 4 C addition had a profound impact on morphology. However, the TiH added sample revealed uneven transition between sediment layers, unstable precipitation process, unstable wall height and wall width, poor morphology, and defects. All SWSs with powder addition revealed the formation of the Al 3 Ti phase. Moreover, the columnar grains between the layers were transformed into equiaxed grains and finer grains at the center of the layers. There was a significant effect of TiH on the grain refinement. The samples with Ti demonstrated superior mechanical properties. The tensile strength and elongation of the SWSs increased by 28 MPa and 4.6% in the parallel additive direction and by 37 MPa and 8.9% in the vertical direction. The addition of Ti also contributed to the even distribution of the mechanical properties in both directions., Competing Interests: The authors declare no conflicts of interest., (Copyright 2023, Mary Ann Liebert, Inc., publishers.)

Owing to several advantages of metallic sodium (Na), such as a relatively high theoretical capacity, low redox potential, wide availability, and low cost, Na metal batteries are being extensively studied, which are expected to play a major role in the fields of electric vehicles and grid-scale energy storage. Although considerable efforts have been devoted to utilizing MXene-based materials for suppressing Na dendrites, achieving a stable cycling of Na metal anodes remains extremely challenging due to, for example, the low Coulombic efficiency (CE) caused by the severe side reactions. Herein, a g-C 3 N 4 layer was attached in situ on the Ti 3 C 2 MXene surface, inducing a surface state reconstruction and thus forming a stable hetero-interphase with excellent sodiophilicity between the MXene and g-C 3 N 4 to inhibit side reactions and guide uniform Na ion flux. The 3D construction can not only lower the local current density to facilitate uniform Na plating/stripping but also mitigate volume change to stabilize the electrolyte/electrode interphase. Thus, the 3D Ti 3 C 2 MXene@g-C 3 N 4 nanocomposite enables much enhanced average CEs (99.9% at 1 mA h cm -2 , 0.5 mA cm -2 ) in asymmetric half cells, long-term stability (up to 700 h) for symmetric cells, and stable cycling (up to 800 cycles at 2 C), together with outstanding rate capability (up to 20 C), of full cells. The present study demonstrates an approach in developing practically high performance for Na metal anodes.

The lack of suitable cathodes is one of the key reasons that impede the development of aqueous zinc-ion batteries. Because of the inherently unsuitable structure and inferior physicochemical properties, the low-valent V 2 O 3 as Zn 2+ host could not be effectively discharged. Herein, we demonstrate that V 2 O 3 (theoretical capacity up to 715 mAh g -1 ) can be utilized as a high-performance cathode material by an in situ anodic oxidation strategy. Through simultaneously regulating the concentration of the electrolyte and the morphology of the V 2 O 3 sample, the ultraefficient anodic oxidation process of the V 2 O 3 cathode was achieved within the first charging, and the mechanism was also schematically investigated. As expected, the V 2 O 3 cathode with a hierarchical microcuboid structure achieved a nearly two-electron transfer process, enabling a high discharging capacity of 625 mAh g -1 at 0.1 A g -1 (corresponding to a high energy density of 406 Wh kg -1 ) and cycling stability (100% capacity retention after 10 000 cycles). This work not only sheds light on the phase transition process of low-valent V 2 O 3 but also exploits a method toward design of advanced cathode materials.

Lithium-sulfur batteries are promising candidates for the next generation of energy storage systems owing to their high energy density, low toxicity and abundant reserves of sulfur. However, sulfur has poor conductivity, large volume change during charge/discharge, and more importantly, the intermediate polysulfide (Li2Sn, 3 ≤ n≤8) produced in the cycling process is easily soluble in the electrolyte resulting in the "shuttle effect", which have greatly limited the commercialization of lithium-sulfur batteries. Therefore, it is of great value to develop optimized sulfur cathode materials to improve electrode conductivity, buffer volume change and restrain the diffusion of polysulfide. In this work, we construct a V-MOF (MIL-47) derived V2O3@C hollow microcuboid with a hierarchical lasagna-like structure through hydrothermal synthesis followed by calcination, and employ it as a sulfur host for the first time. The fast anchoring of polysulfide by V2O3 nanoparticles and the high electronic conductivity of the 3D carbon framework can simultaneously inhibit the "shuttle effect" in the charge-discharge process and accelerate the kinetics of the redox process. Moreover, the special lasagna-like structure with appropriate voids generated during calcination not only provides many sites for sulfur loading, but also effectively alleviates the volume expansion problem during the electrochemical reaction. Therefore, the final fabricated sulfur cathode via the melt impregnation method exhibits good cycling stability (62.3% after 1000 cycles at 1C) and rate performance (663 mA h g-1 at 2C) at a relatively high sulfur loading of 3.7 mg cm-2.

NASCION-type materials featuring super ionic conductivity are of considerable interest for energy storage in sodium ion batteries. However, the issue of inherent poor electronic conductivity of these materials represents a fundamental limitation in their utilization as battery electrodes. Here, for the first time, we develop a facile strategy for the synthesis of NASICON-type NaTi2(PO4)3/reduced graphene oxide (NTP-rGO) Na-ion anode materials from three-dimensional (3D) metal-organic frameworks (MOFs). The selected MOF serves as an in situ etching template for the titanium resource, and importantly, endows the materials with structure-directing properties for the self-assembly of graphene oxide (GO) through a one-step solvothermal process. Through the subsequent carbonization, an rGO decorated NTP architecture is obtained, which offers fast electron transfer and improved Na+ ion accessibility to active sites. Benefiting from its unique structural merits, the NTP-rGO exhibits improved sodium storage properties in terms of high capacity, excellent rate performance and good cycling life. We believe that the findings of this work provide new opportunities to design high performance NASICON-type materials for energy storage.

Sodium-ion batteries (SIBs) are increasingly on demand owning to their prospect as an inexpensive alternative to Li-ion batteries. However, designing electrode materials with satisfactory rate capacity performance requires high electron transport and Na + conductivity, which is extremely challenging. Herein, we report a hexadecylamine (HDA)-mediated synthesis of NaTi 2 (PO 4 ) 3 (NTP) electrodes via one-step solvothermal process. The addition of HDA material (1) enables the formation of a carbon coating that improves the electron conductivity and (2) importantly serves as a structure-directing agent reducing the NTP-impurity phases in which the transport of Na + ions are sluggish. As a result, the synthesized NTP anode delivers superior rate of capacity retention of 77.8% under the 100-fold increase in current densities. Moreover, outstanding specific capacity of 117.9 mAh g -1 at 0.5 C and capacity retention of 88.6% after 1500 cycles at 1 C can be obtained. The findings of this work provide new opportunity to design SIBs electrodes with superior electrical and ionic conductivity.

LiMn x Fe 1-x PO 4 (LMFP) has attracted extensive interest owing to its high safety and appropriate redox potential. Nevertheless, its poor electrochemical kinetics and structural instability, depending on its manganese content, are still limiting its further application. Herein, we realize a concentration-gradient LiMn 0.5 Fe 0.5 PO 4 hollow sphere cathode material with a carbon coating (HCG-LMFP/C) by a facile and controllable two-step solvothermal approach. On the one hand, the porous hollow architecture can sustain excellent structural stabilization against the volume changes that occur during repeated Li + intercalation/deintercalation. On the other hand, the unique concentration-gradient structure with its Fe-rich surface can not only relieve interface deterioration and improve the ionic/electric conductivity due to the active nature of LiFePO 4 , but also guarantees the chemical stability of the LMFP against electrolyte attack and remarkably reduces Mn dissolution, even at elevated temperature. Therefore, the obtained concentration-gradient HCG-LMFP/C cathode shows improved high-rate performance (111 and 78 mA h g -1 at 20 and 60C rates, respectively) and excellent capacity retention (96% after 1000 cycles at the 10C rate) as well as outstanding temperature tolerance (over a temperature range from 40 °C to -10 °C). More importantly, the present gradient strategy opens up a new window for designing high-performance and stable olivine cathodes, which could also be compatible with many other energy-storage materials for various applications.

In this work, based on the superior electrochemical stability of Li 4 Ti 5 O 12 (LTO) electrodes, LiFePO 4 (LFP)/graphite cells with built-in LTO electrodes as reference electrodes were designed and fabricated. The characteristics of the LTO reference electrodes in the fabricated lithium-ion cells were measured and discussed. The experimental data demonstrated that the LTO built-in reference electrodes were simple to prepare and were feasible options for long-term in situ monitoring of the development of potentials and other electrochemical parameters, such as the Li + diffusion coefficient ( D Li ) and electrochemical impedance spectroscopy (EIS) information, for both anodes and cathodes. Moreover, it is believed that the adoption of LTO as a reference electrode could be of great significance for long-term monitoring of the charge and discharge behavior of individual electrodes in other kinds of lithium-ion cells., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Electron transfer and lithium ion diffusion rates are the key factors limiting the lithium ion storage in anisotropic LiFePO4 electrodes. In this work, we employed a facile solvothermal method to synthesize a "platelet-on-sheet" LiFePO4/graphene composite (LFP@GNs), which is LiFePO4 nanoplatelets in situ grown on graphene sheets with highly oriented (010) facets of LiFePO4 crystals. Such a two-phase contact mode with graphene sheets cross-linked to form a three-dimensional porous network is favourable for both fast lithium ion and electron transports. As a result, the designed LFP@GNs displayed a high rate capability (∼56 mA h g(-1) at 60 C) and long life cycling stability (∼87% capacity retention over 1000 cycles at 10 C). For comparison purposes, samples ex situ modified with graphene (LFP/GNs) as well as pure LiFePO4 platelets (LFP) were also prepared and investigated. More importantly, the obtained LFP@GNs can be used as a basic unit for constructing more complex structures to further improve electrochemical performance, such as coating the exposed LFP surface with a thin layer of carbon to build a C@LFP@GN composite to further enhance its cycling stability (∼98% capacity retention over 1000 cycles at 10 C).

In this work, mesoporous carbon-coated LiFePO4 nanocrystals further co-modified with graphene and Mg(2+) doping (G/LFMP) were synthesized by a modified rheological phase method to improve the speed of lithium storage as well as cycling stability. The mesoporous structure of LiFePO4 nanocrystals was designed and realized by introducing the bead milling technique, which assisted in forming sucrose-pyrolytic carbon nanoparticles as the template for generating mesopores. For comparison purposes, samples modified only with graphene (G/LFP) or Mg(2+) doping (LFMP) as well as pure LiFePO4 (LFP) were also prepared and investigated. Microscopic observation and nitrogen sorption analysis have revealed the mesoporous morphologies of the as-prepared composites. X-ray diffraction (XRD) and Rietveld refinement data demonstrated that the Mg-doped LiFePO4 is a single olivine-type phase and well crystallized with shortened Fe-O and P-O bonds and a lengthened Li-O bond, resulting in an enhanced Li(+) diffusion velocity. Electrochemical properties have also been investigated after assembling coin cells with the as-prepared composites as the cathode active materials. Remarkably, the G/LFMP composite has exhibited the best electrochemical properties, including fast lithium storage performance and excellent cycle stability. That is because the modification of graphene provided active sites for nuclei, restricted the in situ crystallite growth, increased the electronic conductivity and reduced the interface reaction current density, while, Mg(2+) doping improved the intrinsically electronic and ionic transfer properties of LFP crystals. Moreover, in the G/LFMP composite, the graphene component plays the role of "cushion" as it could quickly realize capacity response, buffering the impact to LFMP under the conditions of high-rate charging or discharging, which results in a pre-eminent rate capability and cycling stability.

Shell-core nanostructured carbon materials with a nitrogen-doped graphitic layer as a shell and pristine carbon black particle as a core were synthesized by carbonizing the hybrid materials containing in situ polymerized aniline onto carbon black. In an N-doped carbon layer, the nitrogen atoms substitute carbon atoms at the edge and interior of the graphene structure to form pyridinic N and quaternary N structures, respectively. As a result, the carbon structure becomes more compact, showing curvatures and disorder in the graphene stacking. In comparison with nondoped carbon, the N-doped one was proved to be a suitable supporting material to synthesize high-loading Pt catalysts (up to 60 wt %) with a more uniform size distribution and stronger metal-support interactions due to its high electrochemically accessible surface area, richness of disorder and defects, and high electron density. Moreover, the more rapid charge-transfer rates over the N-doped carbon material are evidenced by the high crystallinity of the graphitic shell layer with nitrogen doping as well as the low charge-transfer resistance at the electrolyte/electrode interface. Beneficial roles of nitrogen doping can be found to enhance the CO tolerance of Pt catalysts. Accordingly, an improved performance in methanol oxidation was achieved on a high-loading Pt catalyst supported by N-doped carbon. The enhanced catalytic properties were extensively discussed based on mass activity (Pt utilization) and intrinsic activity (charge-transfer rate). Therefore, N-doped carbon layers present many advantages over nondoped ones and would emerge as an interesting supporting carbon material for fuel cell electrocatalysts.