Search Results (8)

With the growing market of secondary batteries for electric vehicles (EVs) and grid-scale energy storage systems (ESS), driven by environmental challenges, the commercialization of sodium-ion batteries (SIBs) has emerged to address the high price of lithium resources used in lithium-ion batteries (LIBs). However, achieving competitive energy densities of SIBs to LIBs remains challenging due to the absence of high-capacity anodes in SIBs such as the group-14 elements, Si or Ge, which are highly abundant in LIBs. This review presents potential candidates in metal pnictogenides as promising anode materials for SIBs to overcome the energy density bottleneck. The sodium-ion storage mechanisms and electrochemical performance across various compositions and intrinsic physical and chemical properties of pnictogenide have been summarized. By correlating these properties, strategic frameworks for designing advanced anode materials for next-generation SIBs were suggested. The trade-off relation in pnictogenides between the high specific capacities and the failure mechanism due to large volume expansion has been considered in this paper to address the current issues. This review covers several emerging strategies focused on improving both high reversible capacity and cycle stability. Full article

Debye temperatures of α-Sn_xFe_1−xOOH nanoparticles (x = 0, 0.05, 0.10, 0.15 and 0.20, abbreviated as Sn100x NPs) prepared by hydrothermal reaction were estimated with ⁵⁷Fe- and ¹¹⁹Sn-Mössbauer spectra measured by varying the temperature from 20 to 300 K. Electrical properties were studied by solid-state impedance spectroscopy (SS-IS). Together, the charge–discharge capacity of Li- and Na-ion batteries containing Sn100x NPs as a cathode were evaluated. ⁵⁷Fe-Mössbauer spectra of Sn10, Sn15, and Sn20 measured at 300 K showed only one doublet due to the superparamagnetic doublet, while the doublet decomposed into a sextet due to goethite at the temperature below 50 K for Sn 10, 200 K for Sn15, and 100 K for Sn20. These results suggest that Sn10, Sn15 and Sn20 had smaller particles than Sn0. On the other hand, 20 K ¹¹⁹Sn-Mössbauer spectra of Sn15 were composed of a paramagnetic doublet with an isomer shift (δ) of 0.24 mm s⁻¹ and quadrupole splitting (∆) of 3.52 mm s⁻¹. These values were larger than those of Sn10 (δ: 0.08 mm s⁻¹, ∆: 0.00 mm s⁻¹) and Sn20 (δ: 0.10 mm s⁻¹, ∆: 0.00 mm s⁻¹), suggesting that the Sn^IV-O chemical bond is shorter and the distortion of octahedral SnO₆ is larger in Sn15 than in Sn10 and Sn20 due to the increase in the covalency and polarization of the Sn^IV-O chemical bond. Debye temperatures determined from ⁵⁷Fe-Mössbauer spectra measured at the low temperature were 210 K, 228 K, and 250 K for Sn10, Sn15, and Sn20, while that of α-Fe₂O₃ was 324 K. Similarly, the Debye temperature of 199, 251, and 269 K for Sn10, Sn15, and Sn20 were estimated from the temperature-dependent ¹¹⁹Sn-Mössbauer spectra, which were significantly smaller than that of BaSnO₃ (=658 K) and SnO₂ (=382 K). These results suggest that Fe and Sn are a weakly bound lattice in goethite NPs with low crystallinity. Modification of NPs and addition of Sn has a positive effect, resulting in an increase in DC conductivity of almost 5 orders of magnitude, from a σ_DC value of 9.37 × 10⁻⁷ (Ω cm)⁻¹ for pure goethite Sn (Sn0) up to DC plateau for samples containing 0.15 and 0.20 Sn (Sn15 and Sn20) with a DC value of ~4 × 10⁻⁷ (Ω cm)⁻¹ @423 K. This non-linear conductivity pattern and levelling at a higher Sn content suggests that structural modifications have a notable impact on electron transport, which is primarily governed by the thermally activated via three-dimensional hopping of small polarons (SPH). Measurements of SIB performance, including the Sn100x cathode under a current density of 50 mA g⁻¹, showed initial capacities of 81 and 85 mAh g⁻¹ for Sn0 and Sn15, which were larger than the others. The large initial capacities were measured at a current density of 5 mA g⁻¹ found at 170 and 182 mAh g⁻¹ for Sn15 and Sn20, respectively. It is concluded that tin-goethite NPs are an excellent material for a secondary battery cathode and that Sn15 is the best cathode among the studied Sn100x NPs. Full article

The present study investigates the relationship between the local structure, photocatalytic ability, and cathode performances in sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs) using Ni-substituted goethite nanoparticles (Ni_xFe_1−xOOH NPs) with a range of ‘x’ values from 0 to 0.5. The structural characterization was performed applying various techniques, including X-ray diffractometry (XRD); thermogravimetry differential thermal analysis (TG-DTA); Fourier transform infrared spectroscopy (FT-IR); X-ray absorption spectroscopy (XANES/EXAFS), both measured at room temperature (RT); ⁵⁷Fe Mössbauer spectroscopy recorded at RT and low temperatures (LT) from 20 K to 300 K; Brunauer–Emmett–Teller surface area measurement (BET), and diffuse reflectance spectroscopy (DRS). In addition, the electrical properties of Ni_xFe_1−xOOH NPs were evaluated by solid-state impedance spectroscopy (SS-IS). XRD showed the presence of goethite as the only crystalline phase in prepared samples with x ≤ 0.20, and goethite and α-Ni(OH)₂ in the samples with x > 0.20. The sample with x = 0.10 (Ni10) showed the highest photo-Fenton ability with a first-order rate constant value (k) of 15.8 × 10⁻³ min⁻¹. The ⁵⁷Fe Mössbauer spectrum of Ni0, measured at RT, displayed a sextet corresponding to goethite, with an isomer shift (δ) of 0.36 mm s⁻¹ and a hyperfine magnetic distribution (B_hf) of 32.95 T. Moreover, the DC conductivity decreased from 5.52 × 10⁻¹⁰ to 5.30 × 10⁻¹² (Ω cm)^–1 with ‘x’ increasing from 0.10 to 0.50. Ni20 showed the highest initial discharge capacity of 223 mAh g⁻¹, attributed to its largest specific surface area of 174.0 m² g⁻¹. In conclusion, Ni_xFe_1−xOOH NPs can be effectively utilized as visible-light-activated catalysts and active cathode materials in secondary batteries. Full article

Sodium-ion batteries (SIBs) are one of the recent trends in energy storage systems due to their promising properties, the high abundance of sodium in the Earth’s crust, and their low cost. However, the commercialization process of SIBs is in the early stages of development because of some challenges related to electrodes and electrolytes. Electrolytes are vital components of secondary batteries because they determine anode/cathode performance; energy density; operating conditions (electrochemical stability window, open circuit voltage, current rate, etc.); cyclic properties; electrochemical, thermal, mechanical, and dimensional stability; safety level; and the service life of the system. The performance of the battery is based on the structural, morphological, electrical, and electrochemical properties of the electrolytes. In this review, electrolytes used for SIBs are classified according to their state and material, including liquid, quasi-solid, solid, and hybrid, and recent advances in electrolyte research have been presented by considering their contributions and limitations. Additionally, future trends and recent cutting-edge research are highlighted. Full article

The typical two-dimensional layered structure materials, MXenes, are widely used in energy conversion and storage due to their high conductivity, ion transport ability, and rich surface structures. Recently, MXenes and their composites have been widely employed in secondary batteries, especially sodium-ion batteries (SIBs), with obvious performance improvement. As anodic materials, MXenes, metal oxides, metal sulfides, and other materials contain certain advantages in Na⁺ storage, but they individually also suffer from some issues and challenges, such as low conductivity and serious volume change, as well as the associated low capacity and poor cyclability. By virtue of the advantages of MXenes, with their high conductivity and ultrathin two-dimensional structures, the construction of surface-functionalized MXenes and MXene-based composites could effectively improve the conductivity and mass-transport properties of composites, alleviate volume expansion, and, thus, enhance the capacity properties, rate performances, and cycle stability of SIBs. Herein, we review the latest research status of the structural design of MXenes and Mxene-based materials, as well as their applications in SIBs. We briefly introduce the research background and introduce MXenes and SIBs, and focus on their structural designs and corresponding applications in SIBs. Finally, the important challenges of MXene-based materials applied to SIBs are discussed, and the future prospects of MXene-based composite developments in SIBs are presented. Full article

A tin-decorated reduced graphene oxide, originally developed for lithium-ion batteries, has been investigated as an anode in sodium-ion batteries. The composite has been synthetized through microwave reduction of poly acrylic acid functionalized graphene oxide and a tin oxide organic precursor. The final product morphology reveals a composite in which Sn and SnO₂ nanoparticles are homogenously distributed into the reduced graphene oxide matrix. The XRD confirms the initial simultaneous presence of Sn and SnO₂ particles. SnRGO electrodes, prepared using Super-P carbon as conducting additive and Pattex PL50 as aqueous binder, were investigated in a sodium metal cell. The Sn-RGO showed a high irreversible first cycle capacity: only 52% of the first cycle discharge capacity was recovered in the following charge cycle. After three cycles, a stable SEI layer was developed and the cell began to work reversibly: the practical reversible capability of the material was 170 mA·h·g⁻¹. Subsequently, a material of formula NaLi_0.2Ni_0.25Mn_0.75O_δ was synthesized by solid-state chemistry. It was found that the cathode showed a high degree of crystallization with hexagonal P2-structure, space group P6₃/mmc. The material was electrochemically characterized in sodium cell: the discharge-specific capacity increased with cycling, reaching at the end of the fifth cycle a capacity of 82 mA·h·g⁻¹. After testing as a secondary cathode in a sodium metal cell, NaLi_0.2Ni_0.25Mn_0.75O_δ was coupled with SnRGO anode to form a sodium-ion cell. The electrochemical characterization allowed confirmation that the battery was able to reversibly cycle sodium ions. The cell’s power response was evaluated by discharging the SIB at different rates. At the lower discharge rate, the anode capacity approached the rated value (170 mA·h·g⁻¹). By increasing the discharge current, the capacity decreased but the decline was not so pronounced: the anode discharged about 80% of the rated capacity at 1 C rate and more than 50% at 5 C rate. Full article

O3-NaCoO ${}_2$ is a promising cathode material for sodium ion secondary batteries (SIBs). Na ${}_x$ CoO ${}_2$ shows phase separation (PS) into the O3 and O ${}^{\prime }$ 3 phases in the Na concentration range of 0.89 $⩽x⩽$ 0.99. In order to estimate the domain size (r) in the two-phase region, we performed X-ray microdiffraction (XRMD) of thin films of Na ${}_x$ CoO ${}_2$ at x = 0.97 and ∼1. We found that r (≈400 nm) of the O ${}^{\prime }$ 3 domain is comparable to the particle size d (=331 ± 87 nm) in the as-grown O3-NaCoO ${}_2$ film. This observation suggests that individual particles of Na ${}_x$ CoO ${}_2$ are single phase to minimize the strain at the O3–O ${}^{\prime }$ 3 phase boundary. Full article

Manganese hexacyanoferrate (Mn-PBA) is a promising cathode material forsodium-ion secondary battery (SIB) with high average voltage (=3.4 V) against Na. Here,we find that the thermal decomposition of glucose modifies the surface state of Mn-PBA,without affecting the bulk crystal structure. The glucose treatment significantly improves therate properties of Mn-PBA in SIB. The critical discharge rate increases from 1 C (as-grown)to 15 C (glucose-treated). Our observation suggests that thermal treatment is quite effectivefor insulating coordination polymers. Full article