Initial Discharge Research Articles

Additive Strategy Enhancing In Situ Polymerization Uniformity for High-Voltage Sodium Metal Batteries.

In situ polymerization to prepare quasi-solid electrolyte has attracted wide attentions for its advantage in achieving intimate electrode-electrolyte contact and the high process compatibility with current liquid batteries; however, gases can be generated during polymerization process and remained in the final electrolyte, severely impairing the electrolyte uniformity and electrochemical performance. In this work, an in situ polymerized poly(vinylene carbonate)-based quasi-solid electrolyte for high-voltage sodium metal batteries (SMBs) is demonstrated, which contains a novel multifunctional additive N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA). MSTFA as high-efficient plasticizer diminishes residual gases in electrolyte after polymerization; the softer and homogeneous electrolyte enables much faster ionic conduction. The HF/H2 O scavenge effect of MSTFA mitigates the corrosion of free acid to cathode and interfacial passivating layers, enhancing the cycle stability under high voltage. As a result, the 4.4V Na||Na3 V2 (PO4 )2 F3 cell employing the optimized electrolyte possesses an initial discharge capacity of 112.0 mAh g-1 and a capacity retention of 91.3% after 100 cycles at 0.5C, obviously better than those of its counterparts without MSTFA addition. This work gives a pioneering study on the gas residue phenomenon in in situ polymerized electrolytes, and introduces a novel multifunctional silane additive that effectively enhances electrochemical performance in high-voltage SMBs, showing practical application significance.

Double carbon modified CoS2/NiS2 as anode material for efficient lithium storage performance

To address the challenges associated with significant volume expansion and limited electronic conductivity of transition metal sulfides (TMSs) as anode materials in lithium-ion batteries. Nitrogen doped carbon (NC) and carbon nanotubes (CNTs) modified CoS2/NiS2 (Co-Ni-S/NC/CNTs) composites were prepared by a simple chemical precipitation method and sulfurization reaction. Co-Ni-S/NC/CNTs composites have special structure, utilizing NC as carrier and CNTs as cladding layer. When evaluated as anode materials for lithium-ion batteries, the initial discharge specific capacity of Co-Ni-S/NC/CNTs anode delivers 1518.8 mAh g−1 at 0.1 A g−1, and a high reversible capacity of 1137 mAh g−1 is kept after 100 cycles, which is higher than the discharge specific capacity (1117.1 mAh g−1) of the second cycle. At a current density of 0.5 A g−1, a capacity of 468 mAh g−1 is maintained after 300 cycles. The excellent cycling stability of the CoS2/NiS2 anode can be primarily attributed to that CNTs layer can enhance the conductivity of CoS2/NiS2, and the incorporation of NC can effectively improve the infiltration of electrolytes. Meanwhile, the synergistic action of CNTs and NC can mitigate the volume expansion during charging and discharging processes.

Preparation of SiO2/rGO/CNTs composite and application for lithium‐ion‐battery anodes

To mitigate the volume expansion of SiO2 during the processes of charging and discharging, SiO2/rGO/CNTs composite was fabricated as lithium-ion-battery anode. Within this composite, CNTs are dispersed on the flexible rGO, serving as the supporting framework and conductive bridge of SiO2/rGO. This unique arrangement effectively mitigates the volume expansion of SiO2 as well as concurrently enhances its conductivity, resulting in significant improvement of electrochemical performances. As a result, the SiO2/rGO/CNTs anode exhibits an initial discharge capacity of 1521 mA h g−1, with a sustained capacity of 612 mA h g−1 after 200 cycles at 1 A g-1.

High Sulfur Loading and Capacity Retention in Bilayer Garnet Sulfurized‐Polyacrylonitrile/Lithium‐Metal Batteries with Gel Polymer Electrolytes

AbstractThe cubic‐garnet (Li7La3Zr2O12, LLZO) lithium–sulfur battery shows great promise in the pursuit of achieving high energy densities. The sulfur used in the cathodes is abundant, inexpensive, and possesses high specific capacity. In addition, LLZO displays excellent chemical stability with Li metal; however, the instabilities in the sulfur cathode/LLZO interface can lead to performance degradation that limits the development of these batteries. Therefore, it is critical to resolve these interfacial challenges to achieve stable cycling. Here, an innovative gel polymer buffer layer to stabilize the sulfur cathode/LLZO interface is created. Employing a thin bilayer LLZO (dense/porous) architecture as a solid electrolyte and significantly high sulfur loading of 5.2 mg cm−2, stable cycling is achieved with a high initial discharge capacity of 1542 mAh g−1 (discharge current density of 0.87 mA cm−2) and an average discharge capacity of 1218 mAh g−1 (discharge current density of 1.74 mA cm−2) with 80% capacity retention over 265 cycles, at room temperature (22 °C) and without applied pressure. Achieving such stability with high sulfur loading is a major step in the development of potentially commercial garnet lithium–sulfur batteries.

Electrochemically activated Mn3O4 nanoparticles as higher performing electrode than MnO2 for Al-ion batteries – An insight into the crystallographic changes caused by Al3+ intercalation

Aluminium is the third most abundant element in the earth's crust, with a high theoretical capacity and volumetric energy density, making aluminium ion batteries (AIBs) a preferred technology for future large-scale energy storage applications amongst all of the proposed nonlithium-based battery systems. However, the practical realization of AIBs has so far been impeded by the frequent collapse of the host framework of the cathode materials. Here, nanostructure of Mn3O4 is being reported as a cathode material for aqueous AIBs to enhance the specific capacity, rate capability, and cycling stability. The various salts of aluminium were used as an electrolyte to verify how the composition of the electrolyte affected the intercalation and deintercalation of Al3+ in Mn3O4 electrode. In AlCl3 aqueous electrolyte, the Mn3O4 cathode exhibits the highest initial discharge capacity of ∼ 271 mAh g−1, at a high current density of 0.5 A g−1, with an excellent capacity retention of 98 % after 1,000 cycles. The outstanding cycling stability of the synthesized Mn3O4 nanoparticles is established by considering the phase transition from Mn3O4 spinel to MnO2 layered structure. The intercalation/deintercalation of Al3+ into/from the Mn3O4 crystal structure is also being confirmed by analysing the electrochemical performance in NaCl, KCl, and H2SO4 electrolyte.

Design of Nb5+-doped high-nickel layered ternary cathode material and its structure stability

LiNi0.8Co0.1Mn0.1O2 (NCM811) is one of the most promising cathode materials for high-energy lithium-ion batteries, but there are still problems such as rapid capacity decay during charge and discharge and poor cycle performance. Elemental doping can significantly improve the electrochemical performance of high nickel ternary cathode materials. In this work, Nb5+-doped NCM811 cathode material was successfully synthesized. The results show that Nb5+ doping helps to increase the interlayer spacing of the lithium layer, electron transport, and structural stability, thereby significantly improving the conductivity of Li+. At a high voltage of 4.6 V, the initial discharge specific capacity of 1% Nb5+-doped NCM811 cathode material at 0.1 C is 222.3 mAh·g−1, and the capacity retention rate after 100 cycles at 1 C is 92.03%, which is far more than the capacity retention rate of NCM811 under the same conditions (74.30%). First-principles calculations prove that 1% Nb5+-doped NCM811 cathode material shows the highest electronic conductivity and Nb5+ doping will not change the lattice structure, demonstrating the effectiveness of the proposed strategy.

Research on 3D network in-situ grown NiCo2O4 nanowire arrays construction and its energy storage performance

In this paper, NiCo2O4 nanowire arrays are synthesized on 3D NF skeleton by a one-step hydrothermal method and used as anode materials for lithium-ion batteries (LIBs). Dense nanowire arrays are grown in situ on NF skeleton, cross-linked and constructed into 3D network structure. As an anode, it exhibits excellent electrochemical properties. The initial discharge capacity of NiCo2O4/NF is as high as 1316 mAh g−1 at a current density of 0.2 A g−1, and the specific capacity of 790 mAh g−1 can be maintained after 200 cycles. And NiCo2O4/NF can also maintain a specific capacity of 580.37 mAh g−1 at a current density of 1 A g−1 in the rating performance. And transfer resistance after 200 cycles reduced by 53.5%,which shows a tendency to decrease during the reaction process and accelerates the rate of Li+ transfer, improved battery cycling performance. The excellent lithium storage performance is attributed to the high aspect ratio of the nanowires themselves and the stable 3D network structure, which not only facilitates the rapid transfer of substances and diffusion of Li+, but also alleviates the volume change during the charge/discharge cycle. The band gap of NiCo2O4 can be obtained as 0.671 eV by first nature principle calculation, the electrons readily jump from the valence band to the conduction band and have good conductivity. And the diffusion potential barrier is 0.4 eV, which is easily overcome in the experiment and facilitates the transport of lithium ions.

Optimization of Annealing Process of Li6PS5Cl for All-Solid-State Lithium Batteries by Box–Behnken Design

Li6PS5Cl possesses high ionic conductivity and excellent interfacial stability to electrodes and is known as a promising solid-state electrolyte material for all-solid-state batteries (ASSBs). However, the optimal annealing process of Li6PS5Cl has not been studied systematically. Here, a Box–Behnken design is used to investigate the interactions of the heating rate, annealing temperature, and duration of annealing process for Li6PS5Cl to optimize the ionic conductivity. The response surface methodology with regression analysis is employed for simulating the data obtained, and the optimized parameters are verified in practice. As a consequence, Li6PS5Cl delivers a rather high conductivity of 4.45 mS/cm at 25 °C, and ASSB consisting of a LiNi0.6Co0.2Mn0.2O2 cathode and lithium anode shows a high initial discharge capacity of 151.7 mAh/g as well as excellent cycling performances for more than 350 cycles, highlighting the importance of the design of experiments.

Spherical Shell with CNTs Network Structuring Fe-Based Alluaudite Na2+2 δ Fe2- δ (SO4 )3 Cathode and Novel Phase Transition Mechanism for Sodium-Ion Battery.

Iron-based sulfate cathodes of alluaudite Na2+2 δ Fe2- δ (SO4 )3 (NFS) in sodium-ion batteries with low cost, steady cycling performance, and high voltage are promising for grid-scale energy storage systems. However, the poor electronic conductivity and the limited understanding of the phase-evolution of precursors hinder obtaining high-rate capacity and the pure phase. Distinctive NFS@C@n%CNTs (n = 1, 2, 5, 10) sphere-shell conductive networks composite cathode materials are constructed creatively, which exhibit superior reversible capacity and rate performance. In detail, the designed NFS@C@2%CNTs cathode delivers an initial discharge capacity of 95.9 mAh g-1 at 0.05 C and up to 60 mAh g-1 at a high rate of 10 C. The full NFS@C@2%CNTs//HC cell delivers a practical operating voltage of 3.5V and mass-energy density of 140Wh kg-1 at 0.1 C, and it can also retain 67.37 mAh g-1 with a capacity retention rate of 96.4% after 200 cycles at 2 C. On the other hand, a novel combination reaction mechanism is first revealed for forming NFS from the mixtures of Na2 Fe(SO4 )2 ·nH2 O (n = 2, 4) and FeSO4 ·H2 O during the sintering process. The inspiring results would provide a novel perspective to synthesize high-performance alluaudite sulfate and analogs by aqueous methods.

Photocatalytic and Cathode Active Abilities of Ni-Substituted α-FeOOH Nanoparticles.

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 (NixFe1-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 NixFe1-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 (Bhf) 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, NixFe1-xOOH NPs can be effectively utilized as visible-light-activated catalysts and active cathode materials in secondary batteries.

Optimizing pH conditions for impurity removal in closed-loop Li-ion battery recycling

The closed-loop recycling or resynthesis of spent cathode active materials is an emerging hydrometallurgy-based Li-ion battery (LIB) recycling approach. The conventional acidic leaching process generates various impurities in addition to the constituent elements of Ni, Co, Mn, and Li from spent Li[Ni1-x-yCoxMny]O2 (NCM) cathode active materials. It is well known that even a trace amount of these impurities in resynthesized cathode active materials can affect the LIB performance significantly. Therefore, this study aims at investigating the effects of impurities on the physicochemical and electrochemical characteristics of resynthesized NCM by varying pH conditions during the purification of the LIB leachate. After the purification process where the pH is raised from 1.9 to 6.5, Al, Cu, and Zn are completely removed and other impurities including Fe, Mg, Ca, Li, and Na mostly or partially remain in the leachate. The physicochemical properties and LIB performance of resynthesized NCM at different pH conditions are obtained by various analytical techniques. The composition of leachate and cathode active materials is correlated with the initial discharge capacity, rate capability, and cyclability. Resynthesized NCM from the purified leachate shows a similar initial discharge capacity to pristine NCM. While the purification condition at a high pH aggravates the rate capability, the cyclability of resynthesized NCM is enhanced. This established correlation between the pH condition for the impurity removal in the LIB leachate and the LIB performance of resynthesized NCM would trigger the successful implementation of the closed-loop recycling of spent cathode active materials.

A quasi-solid state polymer electrolyte for high-rate and long-life sodium-metal batteries

High-energy rechargeable sodium metal batteries, featuring quasi-solid polymer electrolytes (QSSPEs), hold the promise of improved safety. However, the low ionic conductivity and limited cyclability of QSSPEs at room temperature have paralyzed the efforts to develop energy-dense metal anode batteries. Herein, we report a QSSPE comprising a blend of polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG). Notably, the porosity and the electrolyte uptake capacity of the QSSPE are highly responsive to the concentration of PEG. The optimized PVP-based QSSPE (PVP-PEG 70 30) shows a high ionic conductivity of 1.06 mS cm−1 at room temperature, along with a high transference number of approximately 0.81. A sodium symmetric cell using PVP-PEG 70 30 demonstrates reversible stripping/plating of sodium for over 700 h at a current density of 1 mA cm−2. Furthermore, PVP-PEG 70 30 alters the localized chemistry of the solid electrolyte interphases (SEIs), facilitating the formation of fluorine-rich SEIs. When coupled with a Prussian blue cathode and sodium metal anode, a full cell employing PVP-PEG 70 30 exhibits an initial discharge capacity of 168 mAh g−1, with an average discharge capacity of 125 mAh g−1 for over 600 cycles at 0.5C. Remarkably, this cell can be cycled stably and reversibly at a high rate of 6.5C. These results suggest that PVP-based QSSPE holds great promise as an electrolyte candidate for high-performance sodium metal batteries.

High pressure molding Li10SnP2S12 ceramic electrolyte with low-grain-boundary-resistance for all-solid-state batteries

Pressure can rebuild the structure-function relationship of materials by adjusting their electronic/crystal structure and microstructure. Particularly, ionic transport properties of solid ion conductors with high-symmetry structure are prone to being influenced by pressure. Herein, the effect of pressure on lithium migration and diffusion in sulfide solid electrolyte, tetragonal-phase Li10SnP2S12 (LSPS), throughout grain body/grain boundary and the interface with cathode is studies carefully. Optimal pressure (1.8 GPa) is found to minimize grain boundary resistance and improve interfacial Li+ ion diffusion, which is attributed to more short-circuit of ion migration, greater electrode/electrolyte contact area, and higher interior deviatoric stress, compensating the negative consideration of channel size reduction. Furthermore, we report for first time that powder sulfide LSPS is pressed as ceramic pellet without breakage under 1.8 GPa by two-anvil hydraulic press, and assembled as solid electrolyte within LiFePO4//Li solid-state battery, demonstrating higher initial discharge capacity of 139.62 mAh·g−1 (coulombic efficiency of 99.48%) and favourable cycling stability at room temperature and 0.1C rate. Microstructural modification by controlling the contact and porosity of the LSPS particles is shown effective in decreasing the interfacial and charge transfer resistances and improving the reaction kinetics. The current research provides a more extensive comprehension of solid electrolytes based on LSPS, thus presenting a new and promising approach for practical application distinguished by cost-effective production and improved ionic conductivity.

Mg-doped LiMn0.8Fe0.2PO4/C nano-plate as a high-performance cathode material for lithium-ion batteries

Lithium-ion battery cathode materials with the high-voltage platform have turned into research highlights. Manganese-based olivine material LiMn0.8Fe0.2PO4 (LMFP), which is synthesized by cheap and environmentally friendly raw materials as precursors, has received high attention due to the higher energy density than commercial lithium iron phosphate products. However, similar to the low conductivity of olivine-structured lithium iron phosphate (LiFePO4), the defect of low conductivity of LMFP has also become the obstacle of LMFP further application. To improve the kinetic properties of LMFP, Mg-doped LMFP/C nano-plate are forearmed by a straightforward and controllable solvothermal approach. The results demonstrate that Mg2+ can be validly doped into the sample, and can partially displace Li+ position in LMFP. It has been found that the Mg-doped LMFP/C material Li0.97Mg0.015Mn0.8Fe0.2PO4 (LMFP-2) presents excellent electrochemical performances and more sustainable application prospect in the fields of electric vehicle and grid energy storage batteries, which can provide a high initial discharge capacity of 156.9 mAh g−1 at 0.1C. In addition, even at high rates of 10 and 20C, the discharge capacity of LMFP-2 can still maintain 120.7 and 104.8 mAh g−1, where the discharge process can be completed in only 255 and 110 s. These results indicate that the introduction of Mg2+ at Li+ site can validly upgradation the electron conductivity and Li+ mobility in the material, thus promoting the electrochemical performances. The rapid discharge ability and cyclic performance of the as-prepared materials make them have great application potential in high-performance lithium-ion batteries.

Ambient Air Pollution and Outpatient Morbidities in Bronchopulmonary Dysplasia.

Rationale: Bronchopulmonary dysplasia (BPD) is the most common long-term complication of prematurity. Although socioeconomic status is associated with BPD morbidities, the drivers of this association are poorly understood. In the United States, ambient air pollution (AAP) exposure is linked to both race/ethnicity and socioeconomic status. Furthermore, AAP exposure is known to have a detrimental effect on respiratory health in children. Objectives: To assess if AAP exposure is linked to BPD morbidity in the outpatient setting. Methods: Participants with BPD were recruited from outpatient clinics at Johns Hopkins University and the Children's Hospital of Philadelphia between 2008 and 2021 (N = 800) and divided into low, moderate, and high AAP exposure groups, based on publicly available U.S. Environmental Protection Agency data. Clinical data were obtained by chart review and caregiver questionnaires. Results: Non-White race, home ventilator use, and lower median household income were associated with higher degrees of air pollution exposure. After adjustment for these factors, moderate and high air pollution exposure were associated with requiring systemic steroids (odds ratio, 1.78 and 2.17, respectively) compared with low air pollution. Similarly, high air pollution exposure was associated with emergency department visits (odds ratio, 1.59). Conclusions: This study demonstrates an association between AAP exposure and BPD morbidity after initial hospital discharge. AAP exposure was closely linked to race and median household income. As such, it supports the notion that AAP exposure may be contributing to health disparities in BPD outcomes. Further studies directly measuring exposure and establishing a link between biomarkers of exposure and outcomes are prerequisites to developing targeted interventions protecting this vulnerable population.

Spiny spherical MnCO3@MnO2 cathode material for aqueous zinc ion batteries

The spiny spherical MnCO3@MnO2 cathode material for aqueous zinc ion batteries was designed and constructed. Electrochemical test results revealed that, the spiny spherical MnCO3@MnO2 cathode material had an initial discharge capacity of 598.2 mAh/g at a current density of 0.2 A/g. As the current density increased with the gradient and then decreased to 0.2 A/g, the specific capacity remained at 541.5 mAh/g, indicating the superior performances compared to that of MnCO3. This research showed that this spiny spherical MnCO3@MnO2 has distinctive structural characteristics and can easily embed zinc ions, demonstrating a competitive cycle stability in aqueous systems.

Freestanding carbon fiber-confined yolk-shelled silicon-based anode for promoted lithium storage applications

A flexible carbon fiber-confined yolk-shelled silicon-based composite is reported as an anode material for lithium storage applications. Silicon nanoparticles (Si NPs) are confined by the N-doped hollow carbon cages (Si-NHC) and these uniform dispersed yolk-shell-structured Si-NHC units were encapsulated by the carbon fibers within an interconnected three-dimensional (3D) framework (Si-NHC@CNFs). For the encapsulated yolk-shelled Si-NHC, the void space between the inner Si NPs and outer NHC can accommodate the structural changes of Si NPs during charging/discharging processes, leading to effectively improved structural stability and cycling life. More importantly, all the Si-NHC units were bridged together through a conductive CNFs “highway” to enhance the overall conductivity and tap density further. As observed, Si-NHC@CNFs exhibited an initial discharge capacity of 1364.1 mAh·g−1 at 1000 mA·g−1 and 678.9 mAh·g−1 at 2000 mA·g−1. Furthermore, the reversible capacity was well maintained at 752.2 mAh·g−1 at 500 mA·g−1 after 6000 ultra-long cycles.Graphical abstract

Repeat Fall Risk in Geriatric Patients After Fall-Induced Head Trauma.

Introduction There are many known risk factors for falls, with poor health and physiologic decreases in function as the major contributors to fall risk in older adults. However, risk factors for repeat falls after initial ED discharge are not well-described. This study seeks to prospectively investigate risk factors for short-term repeat falls in geriatric ED patients with fall-related head trauma who do not require hospital admission. Methods This is a prospective study of patients aged 65 years and older with fall-related head trauma who presented to the EDs of two community level I trauma centers. Patients were excluded for intracerebral hemorrhage, admission during initial ED visit, or death in the hospital. Patients were followed for 14 days. Patient characteristics, repeat ED visits, and reason for returns were noted. Results About 2,143 patients were identified as meeting the inclusion criteria. Within 14 days of the initial presentation, 14.1% of patients returned to the ED, with 8.3% presenting with a complaint related to the initial trauma and 2.6% with a new injury. Patients with comorbidities of dementia (OR 3.02, 95% CI, 1.72-5.33, p<0.001), stroke (OR 2.12, 95% CI, 1.05-4.27, p=0.031), and smoking (OR 4.27, 95% CI,1.76-10.37, p<0.001) were significantly more likely to sustain a new injury leading to a repeat ED visit within 14 days. Conclusions After an ED visit due to a fall, over one in 10 patients will re-present to the ED due to a new injury or sequelae from the initial fall. In the immediate period after a fall, enhanced outpatient follow-up or risk mitigation strategies should be considered to lessen return visits and decrease morbidity.

Suppression of Polysulfide Dissolution and Shuttling with Diphenyl Disulfide Electrolyte for Lithium Sulfur Batteries

Lithium-sulfur (Li-S) systems have been rising stars in new battery technologies beyond lithium-ion battery rea, but the dissolution and shuttle of lithium polysulfide seriously deteriorate the cycling performance. Herein, we proposed diphenyl disulfide (DPDS) as the electrolyte additive for Li-S batteries. DPDS can interact with the discharge intermediate S2- 4/S2- 6 ions, changing the stable form of lithium polysulfide in the electrolyte, inhibiting the shuttle of lithium polysulfide, and protecting the lithium anode. The initial discharge specific capacity of a Li-S battery with conventional electrolyte at 0.5 C is 1352.6 mAh/g, and the specific capacity of a Li-S battery with 200 cycles is 790.5 mAh/g. The initial discharge specific capacity of the battery containing 5.0 wt.% DPDS electrolyte at 0.5 C was 1296.3 mAh/g, and the capacity after 200 cycles was 899.9 mAh/g.

The electrochemical performance comparison of the bagasse derived carbon electrode materials prepared from different applied catalyst loading techniques for the iron catalytic graphitization

Catalytic graphitization is considered as a promising process to promote the formation of graphitic structure for the amorphous bio-based carbon material. Different applied catalyst loading techniques require different correlated energies for the catalytic reaction. Therefore, this work aims to extensively study the influence of catalyst loading technique (i.e., ball-milling and impregnation) for iron catalytic graphitization on the crystalline structure and electrochemical performance of the obtained bagasse-derived carbon electrode for lithium-ion batteries. For the ball-milling technique, the Fe powder was milled with different milling periods. In the case of impregnation, different concentrations of FeCl3 solution were used as the different loading content of iron precursors. The bagasse-based carbon products that underwent the iron catalytic graphitization process showed a better-ordered graphitic structure than the un-processed ones. The catalyst impregnation could sustain the natural porous structure of the bagasse parent, whereas the ball-milling caused the destruction of the carbon structure. Achieved from the impregnation, Fe850-1.4 M sample exhibited the greatest ordered structure, exerting the lowest ID/IG value of 1.2, as well as the largest surface area of 351.9 m2. g−1. This modified bagasse carbon material delivered a high initial specific discharge capacity of up to 863 mAh.g−1 and reversible discharge capacities of 343.1 mAh.g−1 at 0.5C after 50 cycles. This finding suggests that iron catalytic graphitization through impregnation could be a promising process to promote the formation of graphitic structures for other potential biomass-based carbon precursors.