Papers by Keyword: Lithium-Ion Battery

Abstract: Lithium-rich manganese-based oxides (Li_1.2Mn_0.54Ni_0.13Co_0.13O₂, LMNCO) as cathode materials were prepared by the sol-gel method. Then, LMNCO was coated with γ-basic manganese oxide (γ-MnOOH) to form the composite cathodes. Through the structural characterization and performance test, it is found that the composite cathode with 10% γ-MnOOH coating exhibits the best electrochemical performance. After 50 cycles at 0.1 C (1 C = 200 mA g^-1), the specific discharge capacity is 264.4 mAh g^-1 with capacity retention of 96.1%. Even at a high current density of 1C, its discharge capacity reaches up to 200.5 mAh g^-1 after 30 cycles, which suggests that surface coating of γ-MnOOH is an effective strategy for further enhancing the electrochemical performance of LMNCO.

Abstract: A separator is one of the main components of lithium-ion batteries. It separates the cathode and anode while allowing the exchange of ions, and reduces the risk of a short circuit that can cause battery failure. In this study, membranes consisting of electrospun, SiO₂-containing, poly(vinylidene fluoride) nanofibers were synthesized for use as separators in lithium-ion batteries. Moreover, this study investigated the effect of the volume of colloidal SiO₂ (1, 2, and 3 mL) in the precursor (a PVDF/SiO₂ solution containing 10 mL of PVDF solution) on the properties of an associated nanofiber membrane and its performance in a coin cell battery. It was found that the porosity, mechanical strength, and thermal resistance of PVDF/SiO₂ nanofiber membranes increase with the increasing volume of colloidal SiO₂ in the precursor. The PVDF/SiO₂ precursor containing 3 mL SiO₂ produces an optimal membrane separator with a porosity of 67%, thermal shrinkage ratio of 1.3%, and elongation at break of 24%. These results show that PVDF/SiO₂ separators have higher porosity rates than pp and PE membrane separators. Furthermore, the corresponding coin cell battery achieves the highest charge and discharge capacities, i.e., 2.36 and 1.36 mAh/g, respectively.

Abstract: Li₄Ti₅O₁₂ (lithium titanium oxide) or LTO is extensively utilized as active material in Li-ion battery anode mainly due to its zero strain properties and excellent lithium-ion intercalation/deintercalation reversibility with negligible volumetric change. However, LTO is still faced with low electronic conductivity problem, thus the addition of another material such as graphene is necessary to overcome. In this study, LTO was synthesized using sol-gel method with addition of Li varied from 35, 40 and 55 wt% which was controlled by addition of Li₂CO_3. XRD analysis was performed to investigate the crystal structure and phase characteristic of synthesized powder. The results revealed that LTO with addition of 55 wt% Li exhibited the highest purity of Li₄Ti₅O₁₂ phase of 97.7%. It was then added with 5 wt% of graphene. Two-coin cells of Li-ion batteries were made from LTO powders without and with graphene addition as active materials for anode and their electrochemical performances were analyzed. LTO without and with graphene show conductivity of 3.40710^-5 and 2.48810^-5 S/cm, while obtained specific capacity was about 140 mAH and 85 mAh, respectively. This would require further optimization for current experimental condition particularly on graphene addition.

Abstract: Lithium-ion batteries have received much attention for their potential use in electric vehicles (EV's) and portable electronic devices. Fabrication of lithium ion (Li-ion) batteries via ecologically sound (green) processes is also of great interest. Typically, in the production of cathode electrodes, organic solvents such as N-methyl-pyrrolidone (NMP) are used, but these chemicals are toxic. Water-based processing of LiNi_0.6Mn_0.2Co_0.2O₂ (NMC) for manufacturing cathode electrodes can provide a more environmental friendly option. In this work, water soluble styrene butadiene copolymer (SBR) and carboxymethyl cellulose (CMC) are used as binders. The active material ratio was set at 90%. The electrochemical performance of water-based NMC electrodes is examined. Additionally, various conductive agents were considered including acetylene black (A) and graphite (B). The particle sizes of conductive agent affect the electrochemical performance of the batteries. Our results show that replacing the conventional organic solvent-based manufacturing route for NMC cathodes with a water-based process is a promising way to fabricate Li-ion batteries with comparable electrochemical behavior, while avoiding toxic process materials and simultaneously reducing the overall manufacturing costs.

Abstract: Li₄Ti₅O₁₂/SnO₂ composite with different SnO₂ contents were prepared by hydrothermal method. SnO₂ nanosheets were in situ formed on the surface of Li₄Ti₅O₁₂ nanoparticles. At the same time, Sn ions were doped into the Li₄Ti₅O₁₂ lattice, which effectively improved the conductivity of Li₄Ti₅O₁₂. When the content of SnO₂ was 8 %, the electrochemical performance of Li₄Ti₅O₁₂/SnO₂ composite was the best. The first discharge specific capacity was 480.54 mAh/g. The capacity remained at 276.8 mAh/g after 200 cycles at 0.1 A/g, and the capacity retention was as high as 87.4% (compared with the 10th cycle).

Abstract: The Li₄Ti₅O₁₂/Co₃O₄ composites were prepared by hydrothermal reaction method with different Co₃O₄ mass content (3%, 7%, 11%, and 15%). The Li₄Ti₅O₁₂ nanoparticles were set in-situ on the Co₃O₄ sheet. Co ion was doped into the Li₄Ti₅O₁₂ lattice. The first cycle specific capacity firstly increased and then decreased with Co₃O₄ content increasing, which the discharge capacity reached the peaking value that the first capacity was 1111 mAh/g and the specific discharge capacity retained 240 mAh/g after 200 cycles. After 200 cycles of charge and discharge, the retention of the capacity was 96.4% at 0.1 A/g, and the retention of the capacity was 98.4% at 0.5 A/g.

Abstract: The first principles study on the LiFePO₄ and FePO₄ crystal has been evaluated using the density functional theory encrypted in the Cambridge Serial Total Energy Package (CASTEP) computer code. The structural properties, electronic properties, and intercalation voltage of the cathode material are presented. Without the Hubbard U parameter, the conventional functional of GGA-PBE and GGA-PBEsol unable to produce the experimental open-circuit voltage (OCV) and band gap (BG) of cathode material correctly. Generally, the value of the lattice parameter, OCV, and BG will increase as the U value is increased. For OCV, the suitable U value for the GGA-PBE and GGA-PBEsol is 3 eV, whereas, for BG, the appropriate U value for both functional is around 4.3 eV to 4.5 eV. Different Hubbard U value is needed for different functional. It is found that GGA-PBEsol + U is the best parameter to calculate the electrical properties of LiFePO_{4 ­­­­}material.

Abstract: Li-ion batteries are one of the most popular energy storage devices widely applied to various kinds of equipment, such as mobile phones, medical and military equipment, etc. Therefore, due to its numerous advantages, especially on the NMC type, there is a predictable yearly increase in Li-ion batteries' demand. However, even though it is rechargeable, Li-ion batteries also have a usage time limit, thereby increasing the amount of waste disposed of in the environment. Therefore, this study aims to determine the optimum conditions and the potential and challenges from the waste Li-ion battery recycling process, which consists of pretreatment, metal extraction, and product preparation. Data were obtained by studying the literature related to Li-ion battery waste's recycling process, which was then compiled into a review. The results showed that the most optimum recycling process of Li-ion batteries consists of metal extraction by a leaching process that utilizes H₂SO₄ and H₂O₂ as leaching and reducing agents, respectively. Furthermore, it was proceeding with the manufacturing of a new Li-ion battery.

Abstract: Lithium-ion battery (Li-ion) is an energy storage device widely used in various types of electronic devices. The cathode is one of its main components, which was developed because it accelerates the transfer of electrons and battery cycle stability. Therefore, the LiNi_xMn_yCo_zO₂ (LNMC) cathode material, which has a discharge capacity of less than 200 mAh g⁻¹, was further developed. Li-Mn-rich oxide cathode material (LMR-NMC) has also received considerable attention because it produces batteries with a specific capacity of more than 250 mAh g⁻¹ at high voltages. The structure, synthesis method, and sintering temperature in the fabrication of LMR-NMC cathode materials affect battery performance. Furthermore, manganese sulphate fertilizer replaces manganese sulphate as raw material for LMR-NMC cathode due to its lower price. The method used in this study was implemented by reviewing previous literature related to Li-ion batteries, Li-ion battery cathodes, synthesis of LMR-NMC cathode materials, and the potential of manganese fertilizers. This review aims to find out the effect of structure, synthesis method, and sintering temperature on LMR-NMC cathodes made from manganese sulphate fertilizer to obtain a Li-ion battery with a high specific capacity, more environmentally friendly, has good cycle stability, and a high level of safety and lower production costs.

Abstract: Lithium-ion batteries have the main component include a positive electrode, negative electrode, liquid electrolyte, and membrane separator. The separator was used to secure the battery by preventing it from short circuits. In this paper, the separator PVDF/SiO₂ (Polyvinylidene fluoride/Silica) nanofiber membrane was synthesized by double jet sprayers electrospinning method on rotating cylinder collector. The SiO₂ colloid nanoparticle concentration was varied at 1000, 2500, and 5000 ppm. The effect of the SiO₂ nanoparticle addition to the PVDF nanofiber membrane to improve membrane characteristics, including porosity, high temperature stability mechanical, mechanical strength, and battery capacity stability, were systematically investigated. The PVDF/SiO₂ results have a fibrous structure with SiO₂ adhering to the fibers' surface. The membrane separator's average thickness is 10.2 micrometers. A large amount of SiO₂ addition (SiO₂ 5000 ppm) on the PVDF nanofibers membrane increased porosity, mechanical properties, and stability at a temperature of 150 °C.