Li ion diffusivity and electrochemical properties of FePO4 nanoparticles acted directly as cathode materials in lithium ion rechargeable batteries

Zhang, S.M.; Zhang, J.X.; Xu, Shuojiong; Yuan, Xiaolei; He, Boying

doi:10.1016/j.electacta.2012.10.029

Cited by 71 publications

(28 citation statements)

References 42 publications

(39 reference statements)

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“…Apart from the charge-transfer resistance, the apparent lithium diffusion coefficient ( D ) could also be calculated with the EIS measurement. The lithium diffusion coefficient was calculated in Table S5 by using the following equation 17 Herein, σ is the Warburg factor, C is the lithium-ion concentration in the cathode, F is the Faraday constant, n is the amount of electrons transferred per molecule redox reaction, A is surface area of the electrode, T is the respective absolute temperature, and R is the universal gas constant. As shown in Figure 5e, a distinctly linear relationship between Z re and ω –0.5 is exhibited.…”

Section: Resultsmentioning

confidence: 99%

“…Fast transportation of lithium ions and electrons is crucial to sustaining rapid charge and discharge processes in the LIBs. Several practical approaches have been applied to overcome the shortcoming of some active materials in this aspect, such as decreasing the particle size, 16,17 mixing particles with conductive agents, and ion doping. 14,18 Among them, the most common way to enhance the conductivity is to coat a carbon layer on the active particle surface.…”

Section: Introductionmentioning

confidence: 99%

“…Unfortunately, the carbon coating method is not appropriate to improve the electrochemical performance of a-FePO 4 because of the phase transformation from the amorphous state to an electrochemically inert hexagonal system at 460 °C. 17 As an alternative method, highly conductive carbon additives such as graphene, carbon nanotubes (CNTs), or carbon black are often applied to a-FePO 4 materials to improve the conductivity of the cathodes. 19−24…”

Section: Introductionmentioning

confidence: 99%

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Amorphous FePO₄/Carbon Nanotube Cathode Preparation via in Situ Nanoprecipitation and Coagulation in a Microreactor

Wang

2019

ACS Omega

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In this article, nanostructured amorphous FePO4 (a-FePO4)–carbon nanotube (CNT) composites, with high purity of FePO4 and a controllable FePO4/C ratio, were directly synthesized by a fast nanoprecipitation process in a microreactor, using Fe(NO3)3 and (NH4)3PO4 as precursors. Oxidized CNTs are well dispersed via strong electrostatic repulsion in a high pH solution system. Subsequently, a-FePO4 nanoparticles are adhered onto CNTs just following the fast nanoprecipitation process; then, the precipitated composites are compacted by ball-milling, forming a compact conductive network with well dispersed and highly loaded active materials. As cathode materials for lithium-ion batteries, the composites exhibit a capacity of 175.8 mAh g–1 at 0.1 C, close to the theoretical capacity (178 mAh g–1), and a good cycle performance with a reversible capacity of 137.0 mAh g–1 after 500 cycles at 5 C. Importantly, the enhanced micromixing enables fast nanoprecipitation in suspension and opens a shortcut for constructing nanostructured composites that have potential in functionalization and are easy to handle.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Amorphous FePO₄/Carbon Nanotube Cathode Preparation via in Situ Nanoprecipitation and Coagulation in a Microreactor

Wang

2019

ACS Omega

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“…Electrochemical impedance spectroscopy (EIS) measurements with the corresponding equivalent circuit are shown in Figure c. Generally, the plots consist of a high‐frequency semicircle and a medium‐frequency semicircle, which overlap each other, and a gradient line in the low frequency region . The values of as‐prepared flower‐like Ni@NiSn samples for R e , R f , R ct , and R total are exhibited in Table S1 of the Supporting Information, which is simulated from EIS data via the equivalent circuit as shown in Figure c inset.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Ni@NiSn Composite with High Lithium‐Ion Diffusion Coefficient for Fast‐Charging Lithium‐Ion Batteries

et al. 2019

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To solve the problems of fast‐charging of lithium‐ion batteries in essence, development of new electrode materials with higher lithium‐ion diffusion coefficients is the key. In this work, a novel flower‐like Ni@SnNi structure is synthesized via a two‐step process design, which consists of the fabrication of Ni cores by spray pyrolysis followed by the formation of SnNi shells via a simple oxidation–reduction reaction. The obtained Ni@SnNi composite exhibits an initial capacity of ≈693 mA h g−1 and a reversible capacity of ≈570 mA h g−1 after 300 charge/discharge cycles at 0.5 C, and maintains 450 mA h g−1 even at a high rate of 3 C. Further, it is proved that a Ni@SnNi composite possesses high lithium‐ion diffusion coefficient (≈10−8), which is much higher than those (≈10−10) reported previously, which can be mainly attributed to the unique flower‐like Ni@SnNi structure. In addition, the full cell performance (Ni@SnNi‐9h/graphite vs LiCoO2) with a capacity ratio of 1.13 (anode/cathode) is also tested. It is found that even at 2 C rate charging/discharging, the capacity retention at 100 cycles is still close to 89%. It means that Ni@SnNi‐9h is a promising anode additive for lithium‐ion batteries with high energy density and power density.

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“…Bên cạnh các ưu điểm hiện có, vật liệu này còn tồn tại một số các nhược điểm cần phải khắc phục như: độ dẫn điện kém (10 −10 S/ cm), độ dẫn ion thấp (10 −14 cm 2 /s), dung lượng thực té tương đối thấp so với dung lượng lí thuyét (~170 mAh/g) 3,4 . Để khắc phục các nhược điểm trên, những nghiên cứu tập trung vào tổng hợp vật liệu có cấu trúc nano bằng phương pháp dung dịch, thủy nhiệt hay sol-gel [5][6][7] Đường cong quá trình oxy hóa cho thấy số ion Li + được phóng thích khỏi cấu trúc vật liệu là khoảng 0,9 ion. Màng điện cực sau quá trình oxy hóa điện hóa, được lắp với cực âm natri kim loại trong hệ pin mô hình Swagelok và thực hiện quá trình đan cài ion Na + .…”

Section: Giới Thiệuunclassified

Investigation of Na-immigration into olivine LiFePO4

Nguyen¹,

Le²,

Huynh³

et al. 2019

Sci. Tech. Dev. J. - Nat. Sci.

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In 21th century, rechargeable batteries are main key of modern technology in many applications from portable devices (smartphone, laptop) to large-scale (hydride electric vehicle-HEV, smart grid system). Among the rechargeable batteries, Li-ion battery (LIB) is outstanding member due to the highest gravimetric as well as volumetric capacity; and Sodium-ion batteries (SIBs) can have contribution to alternating LIBs in large-scale application. Li-ion and Na-ion batteries have the same configuration with an insertion/extraction reversible of Li+ ions and Na+ ions into electrode positive and negative during charge-discharge process. This work aimed to investigate Na-immigration into olivine LiFePO4. The olivine phase LiFePO4 was prepared by hydrothermal process. The synthesized LiFePO4 was characterized the structure, morphology and electrochemical properties. The XRD pattern showed the high crystalline and, the Rietveld refinement with X2 = 2.32% confirmed the highly pure olivine phase without impurity. The SEM images exhibited the uniform and good distribution of synthesized olivine in submicrometric scale. The delithiated phase FePO4 was prepared by electrochemical oxidation at low rate C/20. The charge-discharge curves demonstrated the reversible Na-immigration into olivine host with a highest capacity of 80 mAh/g, the cyclability was found out in 73 mAh/g upon 30 cycles. The ex-situ XRD (electrode after electrochemical oxidation, electrode after Na-insertion) revealed the stability of FePO4 framework during Na-immigration.

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Li ion diffusivity and electrochemical properties of FePO4 nanoparticles acted directly as cathode materials in lithium ion rechargeable batteries

Cited by 71 publications

References 42 publications

Amorphous FePO₄/Carbon Nanotube Cathode Preparation via in Situ Nanoprecipitation and Coagulation in a Microreactor

Amorphous FePO₄/Carbon Nanotube Cathode Preparation via in Situ Nanoprecipitation and Coagulation in a Microreactor

Synthesis of Ni@NiSn Composite with High Lithium‐Ion Diffusion Coefficient for Fast‐Charging Lithium‐Ion Batteries

Investigation of Na-immigration into olivine LiFePO4

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Li ion diffusivity and electrochemical properties of FePO4 nanoparticles acted directly as cathode materials in lithium ion rechargeable batteries

Cited by 71 publications

References 42 publications

Amorphous FePO4/Carbon Nanotube Cathode Preparation via in Situ Nanoprecipitation and Coagulation in a Microreactor

Amorphous FePO4/Carbon Nanotube Cathode Preparation via in Situ Nanoprecipitation and Coagulation in a Microreactor

Synthesis of Ni@NiSn Composite with High Lithium‐Ion Diffusion Coefficient for Fast‐Charging Lithium‐Ion Batteries

Investigation of Na-immigration into olivine LiFePO4

Contact Info

Product

Resources

About

Amorphous FePO₄/Carbon Nanotube Cathode Preparation via in Situ Nanoprecipitation and Coagulation in a Microreactor

Amorphous FePO₄/Carbon Nanotube Cathode Preparation via in Situ Nanoprecipitation and Coagulation in a Microreactor