BULLETIN OF THE KOREAN CHEMICAL SOCIETY
·
2017
·Vol. 38
·期 11
·1269-1274
·
IF 0.602
Liu Wenlong,Jiang Weiwei,Yan Chenran,Feng Wei,Wang Dongxia,Zhao Liming,Feng Tingting,Gong Feng
Li(Ni 0. 8 Co 0 . 15 Al 0 .05 )O 2 (NCA) cathode material for lithium ion batteries is synthesized by calcining Ni–Co–Al hydroxide or carbonate hydroxide hydrate precursor, which is obtained by hydrothermal method, and the NCA cathode material is hierarchical hollow microspheres with the diameter in the range of 3–5 µm and composed of nanoflakes and/or nanowires. The effect of hydrothermal reaction time on the morphologies and the crystalline quality of the NCA cathode material is investigated on the basis of scanning electron microscopy, X-ray diffraction, and tunneling electron microscopy. The NCA cathode material shows smooth and monotonous charge/discharge characteristics, delivers a reversible capacity as 144.4 mAh/g and retains 90.4% after 50 cycles at a current density of 0.1 C between 2.5 and 4.3 V.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2019
·Vol. 26
·期 1
·127-139
·
IF 2.289
Zeng Tianbiao,Zhang Chuhong
The precursor synthesis of the LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) is usually operated in NaOH/NH 3 ·H 2 O aqueous system, and the pH value and the liquid feeding rate need strict control. Herein, a simple synthesis method was investigated without pH and liquid feeding rate control by using urea as the precipitation agent. The relationship of the metal ions’ concentration to the homogeneity of the precursor was studied in detail. To decrease the lattice disordering ratio and increase the reversible capacity of the NCA, polar CTAB molecules were added into the CO(NH 2 ) 2 /H 2 O system. The lattice disordering ratio of the NCA was decreased and the integral electrochemical performances were improved. The stable reversible capacity of the battery in 0.1, 0.5, 1, 2, 3, 4, and 6 C can reach to 188, 173, 167, 162, 152, 143, and 125 mAh g −1 . It is expected that the simple synthesize method may provide some inspiration to the NCA cathode research.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE IONICS
·
2024
·
IF 3
Jiatai Wang,Yan Wang,Shunli Hou,Geng Zhou,Yuanyuan Li,Xiaocen Yan,Changjuan Deng,Xiaoyi Hou,Jian Li
Lithium-ion batteries (LIBs) as energy storage devices have been booming recently to fill the demand for energy requirements. High‑nickel ternary cathode material LiNi 0.815 Co 0.15 Al 0.035 O 2 (NCA), extremely possible to be the next generation of cathode materials for applications due to its high energy density , low cost, and environmental friendliness. However, the rate capability and cycling stability of this cathode material is mediocre. In this work, NCA-based cathode materials have been modified by sodium (Na + ) doping through a high-temperature solid-state reaction, the results show that Na + -doping can effectively improve the electrochemical performance of NCA. Electrochemical test results show that Na + -doping improves Li + diffusion coefficient , inhibits NCA polarization, and reduces the charge transfer impedance. As-prepared 2%Na-NCA at the current density of 1.0C shows a discharge-specific capacity of 149.16 mAh/g and a retention rate of 96.49% after 100 cycles, but the retention rate of the Pure-NCA was (84.47%). Furthermore, 2% Na-NCA shows 121.07 mAh/g at 5.0C, with an increase of 27.05 mAh/g over the Pure-NCA (94.02 mAh/g). The results of the study showed that doping with sodium ions can effectively improve the rate capabilities and cycling stability of NCA.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 18
·14711-14721
·
IF 2.779
Feng Dong,Chen Qiduo,Mei Yi,Chen Xinzhi,Zeng Tianbiao
LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) cathode material was usually prepared with Ni 2+ , Co 2+ , Al 3+ co-precipitation method using NaOH/NH 3 ·H 2 O aqueous solution with strictly control of liquid feeding rate and pH value. In this contribution, a facile method was proposed to co-precipitate Ni 2+ , Co 2+ , Al 3+ for synthesizing NCA using (NH 4 ) 2 C 2 O 4 ·2H 2 O as precipitant without control of pH and liquid feeding rate. The impact of reagents (sulfate reagents, nitrate reagents, chloride reagents, acetate reagents) on morphology, micro-structure and final electrochemical performances of NCA were systematically studied. It was suggested that sulfate reagents are suitable for synthesizing NCA. Furthermore, an optimum synthesis route was further selected for mass production. The NCA delivered reversible specific capacity of about 200 mAh g −1 , 191 mAh g −1 , 177 mAh g −1 , 153 mAh g −1 , 132 mAh g −1 , 115 mAh g −1 , 105 mAh g −1 and 94 mAh g −1 at 0.1 C, 0.5 C, 1 C, 2 C, 3 C, 4 C, 5 and 6 C, respectively. Considering the facile and economical synthesis method of precursor, this work can be a footstone for advancing the practical application of NCA cathodes.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Shiyu He,Aijia Wei,Wen Li,Xue Bai,Lihui Zhang,Xiaohui Li,Rui He,Lili Yang,Zhenfa Liu
The Br − modified LiNi 0.815 Co 0.15 Al 0.035 O 2 (NCA) cathode materials areprepared via a situ doping method for the first time. The structural and electrochemical properties within Br − modified NCA cathode material are in an in-depth analysis. X-ray diffraction (XRD) results show enlarged interslab spacing due to the fact that partial Br − has doped into the bulk particles of NCA to replace O 2− in 6c site. Density functional theory (DFT) calculations suggest that Br − doping mainly occurs in the surface layer. Moreover, the Br ‒ modified NCA cathode materials present smaller primary particles than pure NCA, which is proved by calculations of particle size from random scanning electron microscopy (SEM) images. X-ray photoelectron spectroscopy (XPS) results certify that the the valence state of Ni 3+ is partly reduced to Ni 2+ and residual lithium acts as stable LiBr instead of unstable Li 2 CO 3 at the surface of Br ‒ modified NCA cathode materials. From the electrochemical tests, 0.2 mol% Br − modified NCA with reduced potential polarization, decreasing value of R sf + R ct and increasing Li + diffusion coefficient , exhibits excellent cycling performance, even at elevated temperature. These results clearly indicate that Br − modification contributes to the remarkable enhancement of structure stability and cycling performance of NCA.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2021
·Vol. 28
·期 2
·305-316
·
IF 2.232
Wang Hao-yang,Cheng Xue,Li Xiao-feng,Pan Ji-min,Hu Jun-hua
To probe the coupling effect of the electron and Li ion conductivities in Ni-rich layered materials (LiNi 0.8 Co 0.15 Al 0.05 O 2 , NCA), lithium lanthanum titanate (LLTO) nanofiber and carbon-coated LLTO fiber (LLTO@C) materials were introduced to polyvinylidene difluoride in a cathode. The enhancement of the conductivity was indicated by the suppressed impedance and polarization. At 1 and 5 C, the cathodes with coupling conductive paths had a more stable cycling performance. The coupling mechanism was analyzed based on the chemical state and structure evolution of NCA after cycling for 200 cycles at 5 C. In the pristine cathode, the propagation of lattice damaged regions, which consist of high-density edge-dislocation walls, destroyed the bulk integrity of NCA. In addition, the formation of a rock-salt phase on the surface of NCA caused a capacity loss. In contrast, in the LLTO@C modified cathode, although the formation of dislocation-driven atomic lattice broken regions and cation mixing occurred, they were limited to a scale of several atoms, which retarded the generation of the rock-salt phase and resulted in a pre-eminent capacity retention. Only NiO phase “pitting” occurred. A mechanism based on the synergistic transport of Li ions and electrons was proposed.
研究领域:
材料科学
·
电化学
·
能源存储技术
✓ 已验证
DOI
高影响因子
IONICS
·
2021
·Vol. 28
·期 2
·767-777
·
IF 2.817
Zang Guojing,He Min,Liao Youhao,Li Minsui,Hong Mingyao,Li Weishan
To improve the comprehensive performance of fibrous membrane based on poly(methyl vinyl ether-alt-maleic anhydride) P(MVE-MA)- and poly(vinylidene fluoride-co-hexafluoropropylene) P(VdF-HFP)-blended copolymers, a small amount of nano-Al 2 O 3 was doped by electrospinning technique to apply for high-energy-density cathode material of nickel-rich LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) based Li-ion battery. The results indicated that the electrospinning membrane and corresponding gel polymer electrolyte (GPE) only doped with 3.0 wt.% nano-Al 2 O 3 presented the proper structure and delivered the best electrochemical characterization. Due to the uniform distribution of nanoparticles on the fibers with higher density, the specific surface area and porosity of the fiber membrane were increased, leading to the improved fracture stress of 172.0 MPa for the membrane and ionic conductivity of 2.1 × 10 −3 S cm −1 for the GPE at room temperature. Contributed from the proper pore structure and the enhanced interfacial stability, the capacity retention of 89.4% was achieved for the Li/GPE/NCA coin cell after 200 cycles in the voltage range of 3.0 V and 4.3 V under room temperature using the GPE doped with 3 wt.% Al 2 O 3 , compared with that of 63.6% for the GPE without nanoparticles. Similarly, the discharge capacity of the coin cell under 7 C rate (123.2 mAh g −1 ) maintained 65% of that at 0.3 C (189.4 mAh g −1 ), showing good rate performance of the developed GPE. Therefore, the significant improvement in electrochemical stability of the GPE achieved by doping a small number of nanoparticles provided a simple and feasible solution for the development of high-energy-density Li-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
Energy Storage Materials
·
2018
·
IF 0
Xuelei Li,Ming Liang,Jian Sheng,Dawei Song,Hongzhou Zhang,Xixi Shi,Lianqi Zhang
By virtue of high specific capacity, LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) is considered to have a promising application in all-solid-state lithium batteries (ASSLB) using sulfide electrolyte. However, the interfacial instability between NCA cathode and sulfide electrolyte is still a serious problem, leading to poor rate and cycle performances of NCA cathode. To boost the interfacial instability and boost the rate and cycle performances of NCA cathode, a novel double buffer layer strategy is constructed in this paper. Firstly, NCA is designed as a core-shell structure to achieve self-coating, in which Ni-rich core LiNi 0.85 Co 0.15 O 2 can provide high capacity, and Al-rich shell LiNi 0.6 Co 0.15 Al 0.25 O 2 as the first buffer layer can provide the complete coating on the Ni-rich core. Secondly, a thin inactive LiNbO 3 layer as the second buffer layer is coated on the core-shelled NCA (CS-NCA) particles to increase the interface stability. As expected, LiNbO 3 -coated CS-NCA (CS-NCA@LiNbO 3 ) cathode displays high discharge capacity (184.1 mAh g −1 at 0.06 C), excellent initial coulombic efficiency (90.2%, 0.06 C), outstanding rate performance (130 mAh g −1 at 4.2 C) and cycle performance (capacity retention of 89.4% after 400 cycles at 0.3 C) at 60 °C. The results indicate that this novel double buffer layers strategy is effective to boost rate and cycle performances of NCA cathode for ASSLB using sulfide electrolyte.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
Journal of Energy Chemistry
·
2016
·Vol. 26
·期 3
·481-487
·
IF 2.322
Zhen Zhang,Pengfei Zhou,Huanju Meng,Chengcheng Chen,Fangyi Cheng,Zhanliang Tao,Jun Chen
LiNi 0.915 Co 0.075 Al 0.01 O 2 (NCA) with Zr(OH) 4 coating is demonstrated as high performance cathode material for lithium ion batteries (LIBs). The coated materials are synthesized via a simple dry coating method of NCA with Zr(OH) 4 powders, and then characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Experimental results show that amorphous Zr(OH) 4 powders have been successfully coated on the surface of spherical NCA particles, exhibiting improved electrochemical performance . 0.50 wt% Zr(OH) 4 coated NCA delivers a capacity of 197.6 mAh/g at the first cycle and 154.3 mAh/g after 100 cycles with a capacity retention of 78.1% at 1 C rate. In comparison, the pure NCA shows a capacity of 194.6 mAh/g at the first cycle and 142.5 mAh/g after 100 cycles with a capacity retention of 73.2% at 1 C rate. Electrochemical impedance spectroscopy (EIS) results show that the coated material exhibits a lower resistance, indicating that the coating layer can efficiently suppress transition metals dissolution and decrease the side reactions at the surface between the electrode and electrolyte. Therefore, surface coating with amorphous Zr(OH) 4 is a simple and useful method to enhance the electrochemical performance of NCA-based materials for the cathode of LIBs.
研究领域:
电化学
·
材料科学
·
能源存储
·
电池技术
·
无机非金属材料
·
固态化学
✓ 已验证
DOI
高影响因子
Small
·
2019
·Vol. 15
·期 50
·1904854
·
IF 10.856
Junchao Zheng,Zhuo Yang,Alvin Dai,Linbo Tang,Hanxin Wei,Yunjiao Li,Zhenjiang He,Jun Lu
Although the high energy density and environmental benignancy of LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) holds promise for use as cathode material in Li-ion batteries, present low rate capabilities, and fast capacity fade limit its broad commercial applications. Here, it is reported that surface modification of NCA cathode ( R-3m ) with 5 nm-thick nanopillar layers and Fm-3m structures significantly improves electrode structure, morphology, and electrochemical performance. The formation of nanopillar layers increases cycling and working voltage stability of NCA by shielding the host material from hydrofluoric acid and improves structural stability with the electrolyte. The modified NCA cathode exhibits an enhanced 89% capacity retention at a rate of 1 C over that of pristine NCA (75.2%) after 150 cycles and effectively suppresses working voltage fade (a drop of 0.025 V after 300 cycles) during repeated charge–discharge cycles. In addition, the diffusion barrier of Li ions in NCA crystals at 0.80 V is noticeably smaller than that of Li ions in pristine NCA (0.87 eV). These findings demonstrate that this unique surface structure design considerably enhances cycle and rate performance of NCA, which has potential applications in other Ni-rich layered cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
锂离子电池
·
纳米材料
✓ 已验证
DOI
高影响因子
Nanoscale
·
2025
·Vol. 17
·期 27
·16515-16522
·
IF 5.1
Zhengwei Li,Zixuan Fang,Jiajun Zhu,Wenxi Yang,Yubing Guo,Fan Wang,Jiyang Li,Mengqiang Wu
NCA (LiNixCoyAl1−x−yO2, x ≥ 0.8) cathode materials have become some of the leading candidates for lithium-ion batteries due to their superior specific discharge capacity and more cost-effective production. Yet, NCA materials are facing significant challenges such as surface reconstruction and micro-cracks, which adversely impact their electrochemical performance and practical application. Herein, a simple doping modification strategy using high-valence Mo6+ cations is proposed to address these issues. The experimental analysis results demonstrate the following: (1) the high-valence Mo6+ cations provide additional positive charge and reduce the migration barrier for Li+, thereby improving the Li+ transport kinetics of NCA; (2) Mo6+ doping not only refines the primary particle size, which compacts the stacking of particles, but also optimizes the microstructure of NCA, which prevents the development of micro-cracks and thus enhances the interfacial and bulk-phase stability of NCA; (3) acting as lattice pillars in the TM layers, the high-valence Mo6+ cations increase the thermodynamic barrier for Ni2+ migration from TM sites to lithium sites as well as strengthen the binding with oxygen atoms, thereby suppressing surface reconstruction and oxygen release. Based on the results of electrochemical testing, the prepared Li(Ni0.80Co0.15Al0.05)0.995Mo0.005O2 (NCAM-1) demonstrates a remarkable capacity retention rate of 89.3% after 100 cycles within the voltage range of 3.0–4.3 V and at a rate of 1C, which is significantly higher than the 79.1% retention observed for Li(Ni0.80Co0.15Al0.05)O2 (NCA). Additionally, NCAM-1 delivers a specific discharge capacity of 153.5 mA h g−1 at a high rate of 10C, which is substantially elevated compared to that of NCA (113.5 mA h g−1).
研究领域:
电化学
·
材料科学
·
能源存储
·
固态化学
·
电池技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Xiaoya Gao,Zhimin Li,Honglin Yan,Dongyan Zhang,Yuan Wang,Yuan Ha
Ni-rich layered LiNi 0.80 Co 0.15 Al 0.05 O 2 (NCA) cathode materials have attracted extensive attention in power lithium ion batteries on account of their high specific capacities and low voltage delay. However, they still suffer from inferior cycling stability, especially operating at a high cutoff voltage. In this paper, a surface modification strategy was proposed by utilizing Al(PO 3 ) 3 as a coating material to enhance the cycling performance of NCA in 2.7–4.6 V (vs. Li/Li + ). The surface modification effects of Al 3+ lattice doping and Al(PO 3 ) 3 coating were verified to be well achieved. In particular, besides the functions in stabilizing surface crystal structure of the NCA and isolating the erosion from electrolyte, the Al(PO 3 ) 3 coating could eliminate the residual lithium on the NCA surface to in-situ generate the Li 3 PO 3 which was conductive to the rate performance. Accordingly, the Al(PO 3 ) 3 -modified NCA cathode delivered excellent cycling performance, of which the initial discharge capacity was 235.9 mAh . g −1 at high cutoff voltage of 4.6 V, with a capacity retention of 71.6% after 100 cycles at 1 C. This work demonstrates the feasibility of surface modification on NCA via the phosphate coating with multiple functions, and provides an efficient approach to improve the cycling stability of Ni-rich layered cathode materials at higher cutoff voltage.
研究领域:
材料科学
·
电化学
·
锂离子电池
·
能源存储
·
表面工程
·
固态化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）