Materials For Sodium-ion Batteries Research Articles

Pomegranate Peel-Derived Hard Carbons as Anode Materials for Sodium-Ion Batteries.

Exploring high-performance carbon anodes that are low-cost and easily accessible is the key to the commercialization of sodium-ion batteries. Producing carbon materials from bio by-products is an intriguing strategy for sodium-ion battery anode manufacture and for high-value utilization of biomass. Herein, a novel hard carbon (PPHC) was prepared via a facile pyrolysis process followed by acid treatment using biowaste pomegranate peel as the precursor. The morphology and structure of the PPHC were influenced by the carbonization temperature, as evidenced by physicochemical characterization. The PPHC pyrolyzed at 1100 °C showed expanded interlayer spacing and appropriate oxygen group content. When used as a sodium ion battery anode, the PPHC-1100 demonstrated a reversible capacity of up to 330 mAh g-1, maintaining 174 mAh g-1 at an increased current rate of 1 C. After 200 cycles at 0.5 C, the capacity delivered by PPHC-1100 was 175 mAh g-1. The electrochemical behavior of PPHC electrodes was investigated, revealing that the PPHC-1100 possessed increased capacitive-controlled energy storage and improved ion transport properties, which explained its excellent electrochemical performance. This work underscores the feasibility of high-performance sodium-ion battery anodes derived from biowaste and provides insights into the sodium storage process in biomass-derived hard carbon.

New anode materials for sodium-ion batteries: NixCa2-xAl-Cl LDH and CoyCa2-yAl-Cl LDH prepared from dechlorination wastes

Layered double hydroxides (LDHs) are considered promising materials in energy storage. Herein, we design a one-step ion-exchange route to prepare two new LDH-based materials, NixCa2-xAl-Cl LDH and CoyCa2-yAl-Cl LDH as anode materials for sodium-ion batteries (SIBs), using Ca2Al(OH)6Cl·2H2O (Ca2Al-Cl LDH) generated from disposing of chlorine-containing wastewater as the feed material. The high-electroactive Ni2+ and Co2+ replace a part of low-electroactive Ca2+ in Ca2Al-Cl LDH, forming NixCa2-xAl-Cl LDH and CoyCa2-yAl-Cl LDH materials with tunnel-like and defective structure, and abundant active sites. Density functional theory calculations indicate that the incorporation of Ni2+ and Co2+ effectively drives electron transfer and directly influences the charge density surrounding the active center, thereby enhancing the conductivity of NixCa2-xAl-Cl LDH and CoyCa2-yAl-Cl LDH. Ex situ XRD and XPS analyses demonstrate a redox reaction between Na+ and NixCa2-xAl-Cl LDH/CoyCa2-yAl-Cl LDH during the discharging/charging process. The NixCa2-xAl-Cl LDH and CoyCa2-yAl-Cl LDH materials exhibit excellent electrochemical performance for SIBs. Among them, Ni0.8Ca1.2Al-Cl LDH and Co0.6Ca1.4Al-Cl LDH deliver discharge capacities of 256.9 and 292.8 mAh g−1 after 200 cycles at 0.2 A g−1 and maintain the discharge capacities of 102 and 118.1 mAh g−1 after 600 cycles at 2 A g−1. This study provides a simple and low-cost method to prepare LDH-based anode materials for SIBs. It also provides a new path for the conversion of low-value dechlorination wastes into high-value-added products.

Structural modulation of Na4Fe3(PO4)2P2O7 via cation engineering towards high-rate and long-cycling sodium-ion batteries

Mixed iron-based phosphate Na4Fe3(PO4)2P2O7/C (NFPP) has gradually emerged as a promising cathode material for sodium-ion batteries (SIBs) owing to its affordability and convenient preparation. However, poor electrical conductivity and inadequate sodium-ion diffusion limit the exertion of its electrochemical properties. Herein, a structural modulation strategy based on Cd doping is applied to NFPP to address the above limitations. In situ X-ray diffraction analysis reveals that Cd-doped NFPP (NFCPP) undergoes an incomplete solid-solution reaction driven by Fe2+/Fe3+ redox. Cd doping effectively stabilises the crystal structure, resulting in a minimal 1 % change in unit cell volume during cycling. Density of state calculations indicate that Cd doping reduces the band gap, increases the local electron density and significantly improves electron conductivity. Benefitting from the enhanced electrochemical kinetics and intercalation pseudocapacitance, the optimised Na4Fe2.91Cd0.09(PO4)2P2O7/C (NFCPP@3%) exhibits exceptional rate performance (capacity of 62 mAh/g at 20 C) and ultra-long cycling life (82.7 % after 6000 cycles at 20 C). A full SIB prepared using NFCPP@3% and hard carbon, display a 91 % capacity retention rate at a current density of 130 mA g−1 over 200 cycles. This work demonstrates that doping can effectively enhance electrochemical performance and offers insights into future development of SIBs.

Molybdenum ditelluride as potential negative electrode material for sodium-ion battery

Molybdenum ditelluride as potential negative electrode material for sodium-ion battery

The induced formation and regulation of closed-pore structure for biomass hard carbon as anode in sodium-ion batteries

Biomass hard carbon is regarded as an advanced anode materials for sodium ion batteries (SIBs) since it possesses balanced performance including satisfactory specific capacity, suitable operating voltage window and low cost. Although numerous instances of utilizing biomass-derived hard carbon in SIBs have been observed, the unregulated pore structure of these hard carbon materials significantly constrains the electrochemical performance of SIBs, leading to diminished initial Columbic efficiency (ICE) and plateau capacity. Herein, taking a biomass hard carbon derived from waste camellia seed shells (CSSHCs) as a template, we display a correlation between synthesis conditions and pore structure of CSSHCs. CSSHCs are synthesized via a facile route including pre‑carbonization, purifying, mechanical ball-milling and high-temperature carbonization, and it is found that adjusting the secondary calcination temperature can induce the formation of closed pore structure, which is of great benefit to increase the ICE and the plateau-capacity. Besides, it is also proved that the obtained CSSHCs anodes obey a sodium storage mechanism that can be classified as “adsorption-intercalation-pore filling”, which endows SIBs with a competitive electrochemical performance. Specifically, the obtained biomass hard carbons at 1300 °C exhibits the best electrochemical performance among these anodes with the reversible capacity of as high as 270.0 mAh g−1 and a high ICE of 80.1 %, together with an excellent cycle stability (91.0 % capacity retention after 200 cycles at 0.1C, 1C = 300 mA g−1). Therefore, this study provides a significant exploration and raw material support for the further utilization of the waste biomass and sustainable development of the anode materials for the large-scale application of SIBs.

Iron-decorated N/S co-doped porous carbon for sodium-ion battery anode to achieve high initial coulombic efficiency

Hard carbon materials are preferred as anode materials for sodium-ion batteries due to their abundance, low price, and environmental friendliness. However, doping-based modification usually induces low initial coulombic efficiency (ICE), which seriously affects the practical application of carbon materials. In this work, Fe-modified N/S co-doped porous carbon is prepared using the salt template method. Fe, N, and S are uniformly distributed on the porous carbon to form an interwoven network structure, providing abundant active sites. Moreover, during the electrochemical reaction, FeNx effectively catalyzes the generation of solid electrolyte interface (SEI) film, which reduces the consumption of Na+ in the side reaction, leading to a high initial coulombic efficiency, and at the same time, the stabilized SEI film accelerates the diffusion of electrons and ions, effectively enhancing the multiplication rate performance. The NFSC exhibits a high specific capacity (371.3 mAh/g) by the co-coordination strategy and a high ICE (85.9 %). This study provides new ideas for research based on the modification of carbon materials.

Ca/Li Synergetic-Doped Na0.67Ni0.33Mn0.67O2 to Realize P2-O2 Phase Transition Suppression for High-Performance Sodium-Ion Batteries.

P2-type layered transition metal oxide Na0.67Ni0.33Mn0.67O2 is considered as a promising cathode for advanced sodium-ion batteries due to its high theoretical specific capacity. However, the P2-type cathode suffers severe P2-O2 phase transition during cycling process, resulting unsatisfactory cyclic stability and rate capability. Herein, a Ca/Li co-doped P2-type Na0.62Ca0.05Ni0.33Mn0.57Li0.10O2 (NCNMLO) cathode material was synthesized through a simple sol-gel method. With the synergistic effect of Ca-doping at Na sites and Li substitution at transition metal (TM) sites, the cathode achieves an excellent electrochemical performance due to the inhibited P2-O2 phase transition and improved ion diffusion with Na+/vacancy disordering arrangement. The NCNMLO cathode exhibits a good cyclic stability with 70.8% of capacity retention at 1 C after 200 cycles and excellent rate capability with 40.1 mAh g-1 at 20 C. The dual sites doping strategy provides an effective and simple approach for designing high-performance layered oxide cathode materials for sodium-ion batteries.

High-Entropy and Component Stoichiometry Tuning Strategies Boost the Sodium-Ion Storage Performance of Cobalt-Free Prussian Blue Analogues Cathode Materials.

Prussian blue analogs (PBAs) are appealing cathode materials for sodium-ion batteries because of their low material cost, facile synthesis methods, rigid open framework, and high theoretical capacity. However, the poor electrical conductivity, unavoidable presence of [Fe(CN)6] vacancies and crystalline water within the framework, and phase transition during charge-discharge result in inferior electrochemical performance, particularly in terms of rate capability and cycling stability. Here, cobalt-free PBAs are synthesized using a facile and economic co-precipitation method at room temperature, and their sodium-ion storage performance is boosted due to the reduced crystalline water content and improved electrical conductivity via the high-entropy and component stoichiometry tuning strategies, leading to enhanced initial Coulombic efficiency (ICE), specific capacity, cycling stability, and rate capability. The optimized HE-HCF of Fe0.60Mn0.10-hexacyanoferrate (referred to as Fe0.60Mn0.10-HCF), with the chemical formula Na1.156Fe0.599Mn0.095Ni0.092Cu0.109Zn0.105 [Fe(CN)6]0.724·3.11H2O, displays the most appealing electrochemical performance of an ICE of 100%, a specific capacity of around 115 and 90 mAh·g-1 at 0.1 and 1.0 A·g-1, with 66.7% capacity retention observed after 1000 cycles and around 61.4% capacity retention with a 40-fold increase in specific current. We expect that our findings could provide reference strategies for the design of SIB cathode materials with superior electrochemical performance.

Defect-rich hard carbon designed by heteroatom escape assists sodium storage performance for sodium-ion batteries

Sodium-ion batteries (SIBs) avoids the use of expensive cobalt element, and the abundance of sodium element is high, so it shows great application potential, and the development of sodium-ion battery materials is of great value. Biomass precursors have the advantages of low cost and widely and sufficiently distributed resources, and embody the environmental concept of waste utilization, however, the poor reversible specific capacity and initial coulombic efficiency (ICE) of pristine corn stover-derived hard carbons (CSHCs) limit their practical application value. In this paper, we propose a method to increase the reversible specific capacity of hard carbon and maintain high ICE, introduce heteroatoms into graphene-like nanosheets at low carbonization temperature, then escape heteroatoms through high pyrolysis temperature, create defects in the graphene-like carbon layer and expand the (002) layer spacing. Density functional theory (DFT) calculations show that defects are beneficial to the adsorption of Na+ on graphene-like nanosheets, and Na+ have a lower diffusion barrier between layers rich in defects and extended (002) layer spacing. Compared with the conventional low pyrolysis temperature heteroatom doping process, the present method exhibits superior ICE. In the ester-based electrolyte, the modified hard carbon (D-CSHC) exhibits a superior specific capacity of 284.5 mAh/g and an ICE of 85.9 % as compared to the pristine corn stover-derived hard carbon (233.5 mAh/g, 72.7 %). In addition, the capacity retention rate was 92.6 % after 500 turns of constant current cycles at 0.15 A/g.

Heterogeneous Interface Design with Oxygen Vacancy-Rich Assistance High-Capacity Titanium-Based Oxide Anode Materials for Sodium-Ion Batteries.

Researchers are paying more attention to sodium-ion batteries (SIBs) because of their abundant supply of sodium resources and affordable price. TiO2 offers excellent safety and a long lifespan as an anode material for SIBs. However, the process kinetics is slow due to its limited Na+ storage efficiency, weak conductivity, and irreversible Na+ capture. In order to address these issues, this review uses a mix of the template approach and the double-hydrolysis method to manage the structure and diffusion of TiO2-based anode materials by synthesizing FeTiO3/TiO2 heterostructured double-shell microspheres (FTO). Through the built-in electric field effect caused by their heterostructures, FTO materials improve reaction kinetics, boost electronic conductivity, and lower the diffusion energy barrier of Na+. Their distinctive double-shell structure can increase electrolyte infiltration, shorten the diffusion distance between ions and electrons, and accommodate volume expansion during cycling. Furthermore, the irreversible capture of Na+ and the unfavorable interactions between the surface active site and electrolyte can be successfully inhibited by FTO heterostructures. FTO has an exceptionally high capacity (reaching 362.7 mA h g-1 after 60 cycles at 20 mA g-1) and excellent cycle stability (with a decay rate of 0.0061% after 1000 cycles at 2 A g-1). The strategy of constructing heterogeneous interfaces assists with high-performance SIB anode design.

Prussian White/Reduced Graphene Oxide Composite as Cathode Material to Enhance the Electrochemical Performance of Sodium-Ion Battery.

Prussian white (PW) is considered a promising cathode material for sodium-ion batteries. However, challenges, such as lattice defects and poor conductivity limit its application. Herein, the composite materials of manganese-iron based Prussian white and reduced graphene oxide (PW/rGO) were synthesized via a one-step in situ synthesis method with sodium citrate, which was employed both as a chelating agent to control the reaction rate during the coprecipitation process of PW synthesis and as a reducing agent for GO. The low precipitation speed helps minimize lattice defects, while rGO enhances electrical conductivity. Furthermore, the one-step in situ synthesis method is simpler and more efficient than the traditional synthesis method. Compared with pure PW, the PW/rGO composites exhibit significantly improved electrochemical properties. Cycling performance tests indicated that the PW/rGO-10 sample exhibited the highest initial discharge capacity and the best cyclic stability. The PW/rGO-10 has an initial discharge capacity of 128 mAh g-1 at 0.1 C (1 C = 170 mA g-1), and retains 49.53% capacity retention after 100 cycles, while the PW only delivers 112 mAh g-1 with a capacity retention of 17.79% after 100 cycles. Moreover, PW/rGO-10 also shows better rate performance and higher sodium ion diffusion coefficient (DNa+) than the PW sample. Therefore, the incorporation of rGO not only enhances the electrical conductivity but also promotes the rapid diffusion of sodium ions, effectively improving the electrochemical performance of the composite as a cathode material for sodium-ion batteries.

Layered Oxide Cathode Materials for Sodium-Ion Batteries: A Mini-Review

Layered Oxide Cathode Materials for Sodium-Ion Batteries: A Mini-Review

Sugarcane bagasse derived carbon aerogels as anode materials for sodium-ion batteries

Biomass-derived carbons have been regarded as promising anode materials for sodium-ion batteries due to their tunable physicochemical properties, economic value, and environmental considerations. Nowadays, most of biomass-derived carbon materials are directly prepared through a one-step carbonization process, which may damage the inherent structure of biomass materials. In this work, hydrothermal and freeze-drying pretreatment before carbonization was employed to prepare sugarcane bagasse derived carbon aerogels, which can preserve the unique structure of the biomass material. When utilized as anode materials for sodium-ion batteries, the optimized carbon aerogel delivered an initial discharge capacity as high as 380 mAh g−1 at a current density of 50 mA g−1. After 50 cycles, the reversible specific capacity was still maintained at 248 mAh g−1.

Charge Carrier Dynamics in Bandgap Modulated Covellite-CuS Nanostructures.

Copper Sulfide (CuS) semiconductors have garnered interest, but the effect of transition metal doping on charge carrier kinetics and bandgap remains unclear. In this study, the interactions between dopant atoms (Nickel, Cobalt, and Manganese) and the CuS lattice using spectroscopy and electrochemical analysis are explored. The findings show that sp-d exchange interactions between band electrons and the dopant ions, which replace Cu2+, are key to altering the material's properties. Specifically, these interactions result in a reduced bandgap by shifting the conduction and valence band edges and increasing carrier concentration. It is observed that undoped CuS nanoflowers exhibit a carrier lifetime of 2.16 ns, whereas Mn-doped CuS shows an extended lifetime of 2.62 ns. This increase is attributed to longer carrier scattering times (84 ± 5 fs for Mn-CuS compared to 53 ± 14 fs for CuS) and slower trapping (∼1.5 ps) with prolonged de-trapping (∼100 ps) rates. These dopant-induced energy levels enhance mobility and carrier lifetime by reducing recombination rates. This study highlights the potential of doped CuS as cathode materials for sodium-ion batteries and emphasizes the applicability of metal sulfides in energy solutions.

Anion Doping and Dual-Carbon Confinement Strategies to Synergistically Boost the Sodium Storage Performance of Cobalt-Based Sulfides.

Cobalt-based sulfides (CSs) are generally regarded as potentially valuable anode materials for sodium-ion batteries (SIBs) due to their excellent theoretical capacity and natural abundance. Nevertheless, their slow reaction kinetics and poor structural stability restrict the practical application of the materials. In this study, the dual-carbon-confined Se-CoS2@NC@C hollow nanocubes with anion doping are synthesized using ZIF-67 as the substrate by resorcin-formaldehyde (RF) encapsulation and subsequent carbonization and sulfurization/selenization. RF- and ZIF-67-derived dual-carbon skeleton hollow structures with a robust carbon skeleton and abundant internal space minimize cyclic stress, mitigate volume changes and maintain the structural integrity of the material. More importantly, Se doping increases the lattice spacing of CoS2, weakens the strength of Co-S bonds, and modulates the electronic structure around Co atoms, thereby optimizing the adsorption energy of the material. As a result, the hollow nanocubes of Se-CoS2@NC@C demonstrates excellent electrochemical performance as the anode for SIBs, delivering a high reversible capacity of 549.4 mAh g-1 at 0.5 A g-1 after 100 cycles and a superb rate performance (541.1 mAh g-1 at 0.2 A g-1, and 393.3 mAh g-1 at 5 A g-1). This study proposes a neoteric strategy for synthesizing advanced anodes for SIBs through the synergy of anion doping engineering and dual-carbon confinement strategy.

Simultaneous Tailoring of Chemical Composition and Morphology Configuration in Metal Hexacyanoferrate for Ultrafast and Durable Sodium-Ion Storage.

Metal hexacyanoferrates (MHCFs) with adjustable composition and open framework structures have been considered as intriguing cathode materials for sodium-ion batteries (SIBs). Exploiting MHCFs with ultrafast and durable sodium storage capability as well as comparable capacity is always a goal that many investigators pursue, but remains challenging. Herein, simultaneous tailoring of chemical composition and morphology configuration is carried out to design a hollow monoclinic high-entropy MHCF (HMHE-HCF) assembled by nanocubes for the first time to realize the objective. The "cocktail effect" of high-entropy construction, rich sodium content of monoclinic phase, and unique hollow structure endow HMHE-HCF cathode with fast reaction kinetics and energetically stable performance during continuous charging/discharging processes. As a result, the HMHE-HCF cathode demonstrates superior rate performance up to an ultra-high rate of 100 C (71.1 % retention to 0.1 C), and remarkable cycling stability with a capacity retention of 77.8 % over 25,000 cycles at 100 C, outperforming most reported sodium-ion cathodes. Further, the HMHE-HCF//hard carbon full-cell delivers capacities of 99.0 and 82.3 mAh g-1 at 0.1 C and 10 C, respectively, and retains 98.1 % of the initial capacity after 1,600 cycles at 5 C, demonstrating its potential application for sodium-ion storage.

Revealing an Extended Adsorption/Insertion-Filling Sodium Storage Mechanism in Petroleum Coke-Derived Amorphous Carbon.

Amorphous carbon holds great promise as anode material for sodium-ion batteries due to its cost-effectiveness and good performance. However, its sodium storage mechanism, particularly the insertion process and origin of plateau capacity, remains controversial. Here, an extended adsorption/insertion-filling sodium storage mechanism is proposed using petroleum coke-derived amorphous carbon as a multi-microcrystalline model. Combining in situ X-ray diffraction, in situ Raman, theoretical calculations, and neutron scattering, the effective storage form and location of sodium ions in amorphous carbon are revealed. The sodium adsorption at defect sites leads to a high-potential sloping capacity. The sodium insertion process occurs in both the pseudo-graphite phase (d002 > 0.370nm) and graphite-like phase (0.345 ≤ d002 < 0.370nm) rather than the graphite phase, contributing to low-potential sloping capacity. The sodium filling into accessible closed pores forms quasi-metallic sodium clusters, contributing to plateau capacity. The threshold of the effective interlayer spacing for sodium insertion is extended to 0.345nm, breaking the consensus of insertion interlayer threshold and enhancing understanding of closed pore filling. The extended adsorption/insertion-filling mechanism explains the sodium storage behavior of amorphous carbon with different microstructures, providing theoretical guidance for the rational design of high-performance amorphous carbon anodes.

Carbonization temperature dependent structural modifications of waste coffee grounds derived hard carbons and their electrochemical behaviors as anode materials for sodium ion batteries

Carbonization temperature dependent structural modifications of waste coffee grounds derived hard carbons and their electrochemical behaviors as anode materials for sodium ion batteries

Research Status and Development Direction of Anode Materials for Sodium-ion Batteries

With the depletion of lithium resources, people gradually began to look for alternatives to lithium-ion batteries, and then sodium-ion batteries entered the public eye. In the past decade, sodium-ion batteries have developed at a high speed, establishing the beginning of the post-lithium era in the field of energy storage. This technology focuses on improving the performance of cathode and anode as well as electrolyte and optimising the preparation method of sodium-ion batteries. This paper mainly introduces the research status and development direction of anode materials for sodium-ion batteries. Firstly, the main structure of sodium-ion batteries is briefly introduced, and then it focuses on the electrochemical properties of several key anode materials such as carbon-based, titanium-based, organic-type and alloy-type anode materials, as well as the problems they face, and finally it takes the actual production and industrial application as a starting point to look ahead to the direction of the development of anode materials for sodium-ion batteries.

Interface stabilization strategy realizing low-temperature sodium storage in Sb anode prepared by ball milling method

Antimony (Sb) is an attractive anode material for sodium-ion batteries (SIBs) owing to its low operating potential, low cost, and high theoretical capacity. However, the large volume expansion of Sb during the Na alloying/dealloying process, which greatly limits its application in SIBs. Simultaneously, as the temperature decreases, the formation of a poor coating on the anode surface significantly increase the difficulty of Na+ transmission. Herein, Sb-graphite-NaF (SCF) ternary composites were prepared by an easy to operate and low-cost ball milling method, which significantly improved the cycling stability and extended to the operation temperature of Sb-base SIBs. A small amount of NaF induces the formation of an inorganic-dominated NaF-rich stable solid electrolyte interphase (SEI) on the Sb anode surface, which can cooperate with graphite to inhibit volume expansion of the Sb particles during sodium storage, enhance conductivity and accelerate Na+ diffusion at room and low temperatures. As a result, the SCF electrode with propylene carbonate-base electrolyte delivered a discharge capacity of 458.4 mAh g−1 after 160 cycles at 500 mA g−1 at 20 °C. When matched with diethylcarbonate-based electrolyte at −20 °C, it had a specific capacity of 299.8 mAh g−1 after 120 cycles and a capacity retention rate of 86.2 %. This study shows that the interface stabilization strategy with a suitable electrolyte can improve the cycling stability of anode materials, provide a new idea for constructing NaF-rich SEI, and a new approach for applying Sb-based materials in low-temperature SIBs.