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In this study, high-temperature solid-phase techniques are used to prepare pristine and Mg-modified LiNiO 2 cathode materials. Various characterizations are performed to analyze the morphology, structure, and electrical state of the two materials. Electrochemical tests show that Mg doping effectively improves the electrochemical properties of the materials. In particular, the modified sample exhibits a higher specific discharge capacity of 244.5 mA h g−1 than the pristine sample. Moreover, its maximum capacity retention after 304 cycles at 1 C is 54.1%. In situ X-ray powder diffraction imaging reveals that the modified material has better phase-transition reversibility than the pristine material. Density functional theory calculations indicate that Mg-doped Li sites can accelerate Li+ transport. Atomic force microscopy results demonstrate that Mg-doped Li sites act as supportive skeletons that enhance the mechanical properties of the material. Therefore, the proposed strategy for the Mg doping of Li sites can improve the architecture of LiNiO 2 cathode materials. [ABSTRACT FROM AUTHOR]

Configuring a carbon substrate with low surface polarity seems very important and significant for accelerating the cathode electrochemical performances of the Lithium-sulfur batteries, which is widely regarded as one of the most promising candidates for the next-generation green energy suppliers. The corn starch-derived carbon with in-situ multi-elements doping, initially carbonized by 6 mol/L H 2 SO 4 and then calcined in nitrogen atmosphere, is employed to configure sulfur cathode for Lithium–Sulfur batteries in this study. As-received carbon with randomly distributed graphical domains serves as charge carriers diffusion channels during discharging/charging cycles, thus endowing the cathode considerable excellent performances. Specifically, the loading amount of sulfur in cathode is around 60.31 wt% and the effective utilization efficiency of active reagent sulfur in cathode is up to 60 %. On activating the cathode at 0.114 A g−1 at 0, 25 and 40 °C, the initial discharge capacities of the Lithium–Sulfur batteries with corn starch-derived carbon-based composite cathode (with ∼1.3 mg cm−2 sulfur) are 278.6, 1023.7 and 976.1 mAh∙g−1, respectively. Accordingly, more uniform, and thinner solid electrolyte interphase membrane formed under room temperature activation, leaving in the dramatically diminished R sur value, contributes to the comparable cycling stability and rate performances of as-designed carbon-based sulfur cathode for Lithium–Sulfur Batteries. [ABSTRACT FROM AUTHOR]

Abstract In this study, we have successfully coated the CeO 2 nanoparticles (CeONPs) layer onto the surface of the Ni-rich layered LiNi 0.7 Co 0.2 Mn 0.1 O 2 cathode materials by a wet chemical method, which can effectively improve the structural stability of electrode. The X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS) are used to determine the structure, morphology, elemental composition and electronic state of pristine and surface modified LiNi 0.7 Co 0.2 Mn 0.1 O 2. The electrochemical testing indicates that the 0.3 mol% CeO 2 -coated LiNi 0.7 Co 0.2 Mn 0.1 O 2 demonstrates excellent cycling capability and rate performance, the discharge specific capacity is 161.7 mA h g−1 with the capacity retention of 86.42% after 100 cycles at a current rate of 0.5 C, compared to 135.7 mA h g−1 and 70.64% for bare LiNi 0.7 Co 0.2 Mn 0.1 O 2 , respectively. Even at 5 C, the discharge specific capacity is still up to 137.1 mA h g−1 with the capacity retention of 69.0%, while the NCM only delivers 95.5 mA h g−1 with the capacity retention of 46.6%. The outstanding electrochemical performance is assigned to the excellent oxidation capacity of CeO 2 which can oxidize Ni2+ to Ni3+ and Mn3+ to Mn4+ with the result that suppress the occurrence of Li+/Ni2+ mixing and phase transmission. Furthermore, CeO 2 coating layer can protect the structure to avoid the occurrence of side reaction. The CeO 2 -coated composite with enhanced structural stability, cycling capability and rate performance is a promising cathode material candidate for lithium-ion battery. [ABSTRACT FROM AUTHOR]

This study synthesizes pristine and Nb-doped lithium-rich manganese-based cathode materials by solvothermal and high-temperature solid-phase methods. Analysis by focused ion beam scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy indicates successful Nb doping into the material's bulk structure. Electrochemical evaluation reveals that electrochemical performance is significantly enhanced by Nb doping. The discharge capacity of Nb-0.02 can maintain 271.7 mAh·g−1, and its cycle retention rate is up to 98.50% after 300 cycles at 0.2C; however, under the same parameters, the pristine material's discharge capacity and cycle retention rate are 212.8 mAh·g−1 and 86.68%. The initial coulombic efficiency and initial discharge capacity of Nb-0.02 is 86.94% and 287.5 mAh·g−1, while that of the pristine material is 73.59% and 234.2 mAh·g−1. Density functional theory calculations demonstrate that Nb doping accelerates Li-ion diffusion and stabilizes material structure due to stronger Nb–O bonds from reduced Li-ion migration barrier energy. Thus, the proposed modification strategy for Nb doping can illuminate the structural design of lithium-rich manganese-based cathode materials. • Nb elements are distributed across the surface and in the bulk material. • ICE and cycle performance are significantly enhanced by Nb doping. • DFT calculations confirm that Nb doping accelerates Li-ion diffusion. [ABSTRACT FROM AUTHOR]

Enhancing the kinetic performance of thick electrodes is essential for improving the efficiency of lithium extraction processes. Biochar, known for its affordability and unique three-dimensional (3D) structure, is utilized across various applications. In this study, we developed a biochar-based, 3D-conductive network thick electrode (∼20 mg cm−2) by in-situ deposition of LiFePO 4 (LFP) onto watermelon peel biomass (WB). Utilizing Density Functional Theory (DFT) calculations complemented by experimental data, we confirmed that this The thick electrode exhibits outstanding kinetic properties and a high capacity for lithium intercalation in brines, even in environments where the Magnesia-lithium ratios are significantly high. The electrode showed an impressive intercalation capacity of 30.67 mg g−1 within 10 min in a pure lithium solution. It also maintained high intercalation performance (31.17 mg g−1) in simulated brines with high Magnesia-lithium ratios. Moreover, in actual brine, it demonstrated a significant extraction capacity (23.87 mg g−1), effectively lowering the Magnesia-lithium ratio from 65 to 0.50. This breakthrough in high-conductivity thick electrode design offers new perspectives for lithium extraction technologies. The watermelon peel serves as the substrate, simultaneously supporting the in-situ loading of LFP, thereby forming an LFP/WB thick electrode exhibits high lithium absorption capacity and excellent kinetic performance in high Mg2+/Li+ ratio brine. It achieved an impressive absorption rate of 30.67 mg g−1·min−1 in 10 min and an average lithium extraction of 23.87 mg g−1 from salt lake brine. This approach effectively reduced the Mg2+/Li+ ratio from 65 to 0.50, enabling efficient lithium separation and comprehensive biological resource utilization. [Display omitted] • The comprehensive utilization of biological resources is achieved. • The low efficiency of Li + extraction with thick electrode is effectively solved. • Effectively reducing the Mg2+/Li+ ratio in low-grade brine. [ABSTRACT FROM AUTHOR]

Improving the kinetic performance of thick electrodes is key to enhancing lithium extraction from salt lakes. Nano-melamine foam (MF), known for its unique porous structure, is ideal for building a three-dimensional (3D) conductive network, thereby boosting electrode kinetics. In our study, we developed a thick electrode (20 mg·g−1) with a 3D-conductive network by in-situ growing LiFePO 4 (LFP) onto a nanoscale MF substrate. This electrode exhibited superior kinetic performance and a high lithium adsorption capacity in brine, achieving up to 32.8 mg·g−1 in just 10 min. Remarkably, even in simulated brine with a high Mg2+/Li+ ratio, it maintained an average coulomb efficiency of 62 %, significantly lowering the Mg2+/Li+ ratio from 65.6 to 0.47. It also showed exceptional stability in actual brine, maintaining an average coulomb efficiency of about 56.6 %. Our development of this high conductivity, thick electrode provides new insights into efficient lithium extraction methods. • The introduction of melamine foam significantly enhanced the extraction efficiency of lithium，addressing the low efficiency commonly associated with lithium extraction in salt lakes. • Demonstrated effectiveness of the LFP/MF materials in real salt lake brine environments, highlighting their potential for practical applications. • The construction of 3D network thick electrode provides a new idea for extracting lithium from salt lake. [ABSTRACT FROM AUTHOR]

Lithium-rich manganese-based oxides are included in high-capacity cathodes. Herein we introduce a certain amount of Mg and Na into lithium-rich manganese-based oxide microspheres to overcome the weak cycling performance and poor rate capacity. This work uses the hydrothermal method combined with the high-temperature solid-phase method and CH 3 COONa and C 4 H 14 MgO 8 as dopants. Transmission electron microscopy (TEM), X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and electrochemical characterization are performed to systematically assess the effect of Na and Mg element doping on the morphology, structure and electrochemical characteristics of Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2. The results show that the material has excellent electrochemical performance. These improvements could be related to the presence of Na in Li layers and Mg in TM layers, which can speed up Li-ion diffusion kinetics and improve ionic and electronic conductivity. DFT calculations demonstrate that the injection of Na and Mg reduces the lithium-ion migration barrier energy. This dual-doped modification technique may help researchers better understand how to build high-capacity and stable cathode materials for LIBs. [ABSTRACT FROM AUTHOR]

Layered high-nickel LiNi 0.8 Co 0.1 Mn 0.1 O 2 is a promising candidate of the next generation cathode materials for lithium-ion batteries. However, severe cycling instability and fast capacity drop induced by anisotropic structured change restrict its wide application. To address these defects, the structure design of cathodes is conducted. Herein, a hierarchical layered LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode consisting of orderly stacking hexagonal nanosheets with exposed active {104} facets is successfully synthesized by an improved co-precipitation process and followed with a high temperature lithiation reaction. Benefiting from this unique texture, exposed active {104} facets with lower surface energy supply 3D barrier-free Li+ ion diffusion channels, significantly improving the efficiency of the Li+ diffusion. Moreover, the consistent arrangement of nanosheets in the manner of the {001} facets close attachment is beneficial to alleviate the stress caused by the anisotropic structured change. Thus, this cathode material presents both superior reversible capability (203.8 mAh g−1 at 0.1C, 184.5 mAh g−1 at 1 C, 173.0 mAh g−1 at 5 C and 161.3 mAh g−1 at 10 C) and stable cycling performance (capacity retention of 89.3% after 100 cycles at 1 C, 55.3% after 300 cycles at 5 C and 59.6% after 300 cycles at 10 C). Schematic of single crystal shape evolution of the cathode materials and the corresponding cycle performance of the NCM-3 sample at different rates. [Display omitted] • A hierarchical cathode material consisting of orderly stacking nanosheets with exposed active {104} facets was successfully synthesized. • The exposed active {104} facets with lower surface energy could supply barrier-free Li+ ion diffusion channels. • The consistent arrangement of nanosheets is beneficial to alleviate the stress and inhibit the pulverization of secondary particles. • The hierarchical cathode material presents both superior reversible capability and stable cycling performance. [ABSTRACT FROM AUTHOR]

Using 3D-rGO, an electrode with a three-dimensional conductive network was successfully constructed, which shortened the transmission path of Li+ and showed excellent kinetic properties (the rate in the first 10 min was 3.58mg·g−1·min−1), and it also has a high adsorption capacity (35.8mg·g−1). [Display omitted] • Significant improvement in the kinetic performance of lithium extraction using the LFP/rGO materials, addressing the low efficiency commonly associated with lithium extraction in salt lakes. • Demonstrated effectiveness of the LFP/rGO materials in real salt lake brine environments, highlighting their potential for practical applications. • The development of a three-dimensional conductive network-incorporated thick electrode provides new insights for the fabrication of high-performance lithium extraction electrodes. Constructing thick electrodes with high Li+ adsorption capacity and excellent kinetic performance effectively addresses the low efficiency of lithium extraction from salt lake brines. However, an increase in the content of active material can hinder the Li+ mass transfer within the electrode, resulting in polarization and reduced kinetic performance, which ultimately affects the extraction efficiency. This study synthesized a three-dimensional(3D) conductive network-incorporated thick electrode (∼20 mg/cm2) composed of the redox graphene oxide-loaded LFP(LFP/rGO) composite through an in situ hydrothermal method. The electrode material showed excellent kinetic performance and a high adsorption capacity for Li+ in salt lake brine. Under a constant voltage of 0.8 V in Li+ solution, the Li+ adsorption capacity reached 36.78 mg·g−1 within 10 min, exhibiting an average coulombic efficiency of over 83.53 %. Furthermore, the LFP/rGO composite thick electrode exhibited a Li+ adsorption capacity of 32.82 mg·g−1, along with an average coulombic efficiency of 74.6 %, even in the West Taijinar old brine solution. Additionally, the electrode material demonstrated remarkable cycling stability, maintaining a capacity of 172.09 mAh·g−1 after 50 cycles at a 0.2C rate in a high-concentration salt lake brine. Our preparation strategy offers novel insights for high-performance lithium extraction electrodes. [ABSTRACT FROM AUTHOR]

Carbon spheres, prepared by hydrothermally treating fresh potato starch, is employed as the sulfur host to configure a high-performance cathode substrate candidate for Li–S batteries. As confirmed by experimental results, both the improved the rate and cycle performances of Li–S batteries cathode with gradient sulfur immobilization, are mainly attributed to the confining, adsorption and conduction multi-functions of as-prepared carbon spheres toward polysulfides. Specifically, on starting the discharging/charging cycles, the active material α-S 8 is irreversibly converted to polysulfides and then transformed between β-S 8 and polysulfides during the next charge/discharge cycles. After initialization at 0.1C for 3 cycles, the initial reversible discharge capacities of the Li–S batteries cathode with optimized sulfur amount are 1072.5, 831.3, 780.4, 726.8, 714.3, 702.7 mAh g−1 sulfur at 0.1, 0.5, 1, 2, 3 and 4 C, which is superior to those of the most previously reported reports. Besides that, as-designed potato-derived carbon based composite cathodes exhibits remarkable rate performance and cycling stability even at wide temperature ranging from −40 to 60 °C, which evidently supports the dominant role of as-prepared 3D carbon spheres in boosting the cathode performance for Li–S batteries. [ABSTRACT FROM AUTHOR]

The relationship between ζ-potential and surface defects of micro-nano sized hexagram-like α-Al2O3 particles was investigated in this paper. The 2D α-Al2O3 particles was prepared by the phase transformation of gibbsite precursor by the following steps during calcination in air: Al(OH)3 → AlOOH→a-Al2O3 → θ-Al2O3 → α-Al2O3. Resulting from the varied intensities of surface defects, as-prepared α-Al2O3 samples have different Eg values around 4.5 eV, which is much narrower than that of bulk α-Al2O3. While benefiting from the interface reaction between surface > AlOH0 and water (>AlOH0 + OH−⇋ > AlO− + H2O), as-prepared α-Al2O3 suspensions can reach their specific pHE values after stirring for 8 h at room temperature. And the measured IEP values of Al2O3-1250°C-2 h, Al2O3-1250°C-3 h, and Al2O3–1300 °C-3 h, which remain 2D morphology, are 7.96, 8.67, and 8.86, respectively. This study is significant and useful for making the industrial applications of α-Al2O3 valid. [ABSTRACT FROM AUTHOR]

• Uniformly dispersed MnCO 3 particles has been synthesized. • CO 2 gas was employed as the sole carburizer. • Mesoporous Mn 2 O 3 microparticles has the similar shape with MnCO 3 precursor. • High adsorption capacity is attributed to electrostatic interaction. Taking the importance and significance of wastewater treatment into consideration, mono-dispersed Mn 2 O 3 powders with sphere-like morphology and mesopore features has been firstly synthesized from the thermal decomposition of MnCO 3 which is prepared via a modified carbonization method using CO 2 gas as the sole carbonate source. The measured isoelectric point, the pH value at which the ζ-potential is zero, of uniformly dispersed Mn 2 O 3 particles is 9.13. Benefiting from the surface electrostatic interaction, as-prepared Mn 2 O 3 microparticles has high adsorption capacity up to 135.5 mg/g toward Congo red dye in aqueous solution. Accordingly, the adsorption process of Congo red by Mn 2 O 3 microspheres could be explained by Langmuir isotherm model and the pseudo-second-order kinetic model. Especially, it is necessary to point out that the removal efficiency of Mn 2 O 3 toward Congo red dye still be well maintained at about 90.78% even after five cycles. Therefore, as-prepared Mn 2 O 3 powders has potential application in large-scale wastewater treatment. [ABSTRACT FROM AUTHOR]

The present study introduces a facile triethanolamine-assisted combustion method, wherein stoichiometric hydrate transition metal acetate with and without the addition of triethanolamine (TEA) were dissolved and mixed uniformly in deionized water and heated to burn. The ashes were then grinded and calcinated to synthesize layered LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathode materials. The structure, morphology, and electrochemical performance of two kinds of LiNi 1/3 Co 1/3 Mn 1/3 O 2 materials were investigated and compared systematically. The results indicate that the sample with TEA possesses smaller particles and exhibits less aggregation and a better hexagonal layered structure. On the contrary, the sample with TEA exhibits lower polarization, a better cycling ability, a significantly improved rate performance, and better electronic conductivity. The enhanced electronic conductivity and electrochemical performance may be ascribed to a higher combustion enthalpy and better dispersion in the solvent following the introduction of TEA. This simple synthetic strategy presents a promising synthetic model for the enhancement of electrochemical performance cathode materials for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Al and F co-modified Li 1.6 Mn 1.6 O 4 is prepared for the first time by a facile sol–gel method followed by a solid-state reaction, which can effectively enhance the adsorption performance of the material as an ion-sieve through the triple synergistic reaction mechanism. [Display omitted] • First synthesis of Al and F co-modified Li 1.6 Mn 1.6 O 4. • The triple synergistic effect of co-modification is studied. • High-temperature in-situ XRD was used to demonstrate the ability of co-modification to improve the structural stability. • The mechanism of action of co-modification was revealed by DFT-based theoretical calculations. A surge of interest has been attracted by Li 1.6 Mn 1.6 O 4 -type adsorbent for collecting lithium resources from salt-lake brines due to its excellent selectivity, high theorical adsorption capacity up to 72. 3 mg g−1 and low cost. However, its large-scale practical application is limited because of its bone element Mn dissolution during the cycled desorption process. Herein, F and Al co-modifying technique, an efficient method for stabilizing its spinel structure or forming protective coating, was employed to improve the application performances of Li 1.6 Mn 1.6 O 4 -type adsorbent prepared by sol–gel method. Based on the various characterization results, the co-modification not only leads to the formation of fluoride-rich coating and the substitution of Mn3+ by Al3+, but also generates the active adsorbents with abundant nano-islands. DFT calculations revealed that the coating layer is indeed AlF 3 rather than LiF. In addition, in-situ high-temperature XRD tests demonstrates that the co-modification can significantly enhance the heat resistance and structural stability of the material. As-prepared adsorbent exhibits greatly improved Li adsorption capacity (increased from 28.5 to 33.7 mg g−1), lower Mn loss rate (decreased from 2.1 to 1.8%), enhanced cycling stability and good adsorption selectivity in the Qarhan brine containing Na+, K+, Ca2+, Mg2+, which is very significant and important for effectively removing lithium from low-grade brines. [ABSTRACT FROM AUTHOR]

Solid-phase reactions were used for the synthetization of the spinel Li 1.6 Mn 1.6 O 4 powder and the lithium ion-sieve MnO 2 ·0.5H 2 O was subsequently obtained by the leaching of the lithium. The physical characterization showed that the polycrystalline precursor and the MnO 2 ·0.5H 2 O were nearly pure spinel, as well as that during the process of the adsorption-desorption, the structural stability was high. The Langmuir isotherm and pseudo second-order kinetics model showed consistency with the adsorption behavior, which indicated the presence of homogeneous adsorption sites for the lithium adsorption and that its process was chemisorption. Adsorbents were found to remain being characterized with a relatively high Li+ uptake (26.13 ​mg ​g−1) with low manganese extracted (1.71%) after the circulation experiment was performed up to 5 times, proving a significant repeatability and stability for the lithium ion-sieve. The concentration factors exhibited the highly selective adsorption capacity for absorbent from Qarhan raw brine with high concentrations of Na+, K+, Ca2+, Mg2+. The adsorbents could be efficiently used for Li+ recovery from Salt Lake brine as well as its excellent potential for further application. Due to the sieving effect (steric hindrance effect and hydration free energy effect), the lithium ion-sieve selectively adsorbed Li+ when the ion-sieve was immersed in brine, indicating that the ion-sieve MnO 2 ·0.5H 2 O was expected to recover Li+ from the solutions including Salt Lake brine, seawater, and wastewater. Image 1 • The precursor was prepared by practical two-stage solid-phase sintering technique. • The Li 1.6 Mn 1.6 O 4 exhibited excellent adsorption performance. • The materials showed the highly selective adsorption from Qarhan raw brine. [ABSTRACT FROM AUTHOR]