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
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
Frontiers in Chemistry
·
2020
·
IF 3.693
Chen Pin,Kong Jingyang,Wang Xin,Ma Weiye,Yang Xia,Qin Yuqing,Hu Xiaohong
Synthesized polypeptide is attracting an increased interests due to its excellent biological characteristic and adjustable chemical properties in bio-related fields. But polypeptide itself has no switching properties, which is harmful to the development of its application as a control component. Herein, light-responsive poly(γ-benzyl-L-glutamate)s (PBLGs) is synthesized by a one-step NCA method using p-aminoazobenzene (m-AZO) and p-diaminoazobenzene (m-DAZO) as initiators. PBLGs exhibit amorphous characteristics with obvious Tg transition, which are 14°C for PBLG1 and 21°C for PBLG2. In order to forecast the structure-property information of PBLGs, theoretical UV-vis spectra as well as the energy gap between HOMO and LUMO is calculated by DFT calculation. Experimental results of UV-vis spectra exhibit similar characteristics to those of theorical UV-vis spectra except for the 40–50 nm red-shifting of absorbance peak. Furthermore, the absorbance intensities of PBLGs have a good linear relationship with their concentration, but their linearity range depending on concentration is completely different. Then, trans–cis transition under a different excitation source and cis–trans recovery in a dark environment are tracked in real-time by UV-vis spectra to evaluate the light response performances. It is found that UV light is the only effective excitation source for PBLG1, and blue light is another effective excitation source for PBLG2 besides UV light. Furthermore, the addition of alcohol and water as cosolvents has little effect on trans→cis transition in UV-light-excited systems, but it shortens recovery time of the cis→trans process in a dark environment. By contrast, the detectable isomerization process becomes unclear with the addition of alcohol in blue-light-excited system. Furthermore, either alcohol or water in solvents accelerate both the trans→cis and cis→trans process in a blue-light-excited system.
研究领域:
高分子化学
·
生物材料科学
✓ 已验证
产品关联
DOI
PubMed
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
MACROMOLECULAR BIOSCIENCE
·
2015
·Vol. 15
·期 6
·829-838
·
IF 3.851
Haiyang Yu,Zhaohui Tang,Dawei Zhang,Wantong Song,Taicheng Duan,Jingkai Gu,Xuesi Chen
A novel random copolypeptide of ornithine, arginine, glycine, and aspartic acid [Poly(ornithine-co-arginine-co-glycine-co-aspartic acid), Poly(O,R,G,D)] has been prepared through ring-opening polymerization of N -δ-carbobenzoxy-l-ornithine N -carboxyanhydride [Orn(Cbz)-NCA)], l-glycine N -carboxyanhydride (Gly-NCA) and β-benzyl l-aspartate N -carboxyanhydride [Asp(Bn)-NCA], following by subsequent deprotection and guanidization. The structure of Poly(O,R,G,D) was confirmed by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). Low cytotoxicity of Poly(O,R,G,D) was confirmed from MTT assay. The Poly(O,R,G,D) contain some internal sequences of RXXR ( X = O, R, G, or D) that could be proteolytically cleaved to expose the cryptic CendR element and bind to Neuropilin-1. This would lead to vascular and tissue permeabilization. Therefore trypsin-cleaved Poly(O,R,G,D) increase the vascular leakage of Evans blue from dermal microvessels at the injection site in vivo skin permeability assay. The intratumoral injection of the Poly(O,R,G,D) significantly enhanced the concentration of cisplatin-loaded nanoparticles in MCF-7 solid tumors. These results show that Poly(O,R,G,D) could increase the vascular leakage and tissue penetration of nanoparticles in a solid tumor and can be used as a potential polymeric tumor-penetrating agent.
研究领域:
生物化学
·
肿瘤学
·
药剂学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Yunong Qin,Wanzhihan Zhang,Rui Wang,Ling Li,Xiaohui Zhao,Wenming Zhang
Herein, a novel strategy to establish a porous FeS–Co9S8/carbon aerogel (FeS–Co9S8/NCA) electrocatalyst for oxygen evolution reaction (OER) is fabricated via applying a green biomass carrageenan sulfuration method to CoFe–metal–organic frameworks (MOFs). The FeS–Co9S8/NCA exhibits optimized catalytic activity toward the OER with a lower overpotential of 322 mV, which is overmatched to the majority of transition metal sulfides (TMSs), as well as lifted long-term durability without evident variation in the LSV curves after 3000 cycles. Rechargeable liquid zinc–air battery (ZAB) assembled with FeS–Co9S8/NCA as the OER catalyst indicated a maximum power density of 176 mW cm–2 and superior cycling stability without raised polarization even after 48 h, outperforms commercial RuO2-based ZAB. Furthermore, the flexible solid-state ZAB built with FeS–Co9S8/NCA also demonstrated outdistance properties and bendability. The excellent performance stems from the hierarchical porous aerogel structure, which offers a multiscale mass/electron transport channel, together with the interfacial synergy effect between FeS and Co9S8, which serves as the active site of the OER reaction. Thus, this work instituted a novel strategy for obtaining both clean and efficient transition metal sulfide electrocatalysts for the OER reaction and an environmentally friendly biomass material-based sustainable electrocatalyst.
研究领域:
材料科学
·
电化学
·
能源存储
·
可持续化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Protocols
·
2024
·
IF 13.1
Wu Yueming,Chen Kang,Wang Jiangzhou,Dai Wenhui,Yu Haowen,Xie Xinyi,Chen Minzhang,Liu Runhui
Synthetic polypeptides, also known as poly(α-amino acids), have the same polyamide backbone structures as natural proteins and peptides. As an important class of biomaterials, polypeptides have been widely used because of their biocompatibility, bioactivity and biodegradability. Ring-opening polymerization of N -carboxyanhydride (NCA) is a classical and widely used method for the synthesis of polypeptides. The dominantly used primary amine–initiated NCA polymerization can yield well-defined polymers and complex macromolecular architectures, but the reaction is slow and sensitive to moisture, making it necessary to use anhydrous solvents and a glovebox. One solution is to use lithium hexamethyldisilazide (LiHMDS) as the initiator, as described in this protocol. LiHMDS-initiated NCA polymerization is less sensitive to moisture and can be carried out in an open vessel outside the glovebox. It is also very fast; the reaction can be complete within 5 min to produce 30-mer polypeptides. In this protocol, poly(γ-benzyl- l -glutamate) is prepared as an example, but the protocol can easily be adapted to the synthesis of other polypeptides by generating NCAs from different amino acids, making it particularly suitable for the efficient parallel synthesis of polypeptide libraries. We provide detailed procedures for NCA synthesis and purification, the method of polymer end-group modification and measurement of polymerization kinetics and reactivity ratio. The procedure for synthesis of monomers and polymerization to form polypeptides requires <1 d. The superfast and open-vessel NCA polymerization method described here will probably enable a wide range of applications in the synthesis and functional study of polypeptide biomaterials.
研究领域:
生物化学
·
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Energy
·
2020
·
IF 5.604
X. Huang,J. Duan,J. He,H. Shi,Y. Li,Y. Zhang,D. Wang,P. Dong,Y. Zhang
Rapid moisture and carbon dioxide uptake in Ni-rich materials deteriorates their processing properties, thermal stability and electrochemical performance. Water washing is a widely used method to efficiently remove Li-based residues from these materials. In this paper, a detailed investigation of ion behavior during washing was carried out for LiNi 0.815 Co 0.15 Al 0.035 O 2 (NCA). Multiple characterizations including inductive coupled plasma atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) depth profiles show that certain amount of Li + and Al 3+ are lost from the near-surface of NCA during washing process, which is one of the key issues that lead washed samples suffer from poor electrochemical performance and structural stability. The excess LiOH·H 2 O ratio in mixing and high temperature sintering during NCA synthesis has a remarkable effect on the Al 3+ dissolution ratio, and the loss rate of Al 3+ is as high as 23.14% for lithium excess ratio up to 10 at.%. Characterization analyses of the electrochemical performance, structure, morphology and elemental chemical state of the samples demonstrate that the dissolution of Li + and Al 3+ from NCA deteriorates the cyclic performance, structural stability and thermal stability.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 31
·15856-15862
·
IF 3.708
Jingjing Wang,Chu Gong,Yinong Wang,Guolin Wu
For the purpose of tumor-specific drug delivery applications, a magnetic and pH dually responsive nano-carrier with a multilayer core–shell architecture was prepared from amine-functionalized Fe3O4@SiO2 through the surface-initiated ring opening polymerization of benzyl-L-aspartate N-carboxyanhydride, and then coated with α-methoxy poly(ethylene glycol) (mPEG) via a pH-sensitive benzoic–imine bond. In order to control the layer thickness of poly(benzyl-L-aspartate) (PBLA), a surface passivation agent was applied to modulate the amino density of the functionalized Fe3O4@SiO2 initiator. In this system, the Fe3O4@SiO2 nanoparticles function as a superparamagnetic core used to target the drug loaded nanocarriers to the pathological site. Meanwhile, the mPEG and PBLA segments serve as a pH-sheddable hydrophilic corona and a hydrophobic middle layer used to load the drug via hydrophobic interactions. The obtained materials were characterized by FT-IR, 1H NMR, DLS, zeta-potential, TEM, TGA and hysteresis loop analysis. Furthermore, the loading and release behavior of doxorubicin on the nanocarrier was investigated and it was shown that the drug loaded nanoparticle was relatively stable under physiological conditions and quickly released in response to acidity due to the shedding of mPEG shells through the pH-cleavage of intermediate benzoic–imine bonds. This pH and magnetic responsive nanoparticle has appeared highly promising for the targeted intracellular delivery of hydrophobic chemotherapeutics in cancer therapy.
研究领域:
生物材料学
·
药剂学
·
癌症治疗
✓ 已验证
产品关联
DOI
高影响因子
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
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Honglin Yan,Xiaoya Gao,Xiangting Yue,Yuan Ha,Zhimin Li
Ni-rich LiNi 0.80 Co 0.15 Al 0.05 (NCA) cathode material with high energy density always suffers from structural degradation during cycles, resulting in rapid capacity fading and severe voltage decay. In this study, a solid-state electrolyte film of Li 1.8 Sc 0.8 Ti 1.2 (PO 4 ) 3 (LSTP) is constructed on the surface of NCA cathode via a chemical route to enhance the cycling stability of NCA cathode. The Ex-situ XRD, EIS, dQ/dV, and SEM analyses show that the structural degradation of NCA derives mainly from the corrosion of electrolyte rather than H2-H3 phase transition, which gives rise to the extremely weak phase transitions of H1-M−H2−H3 after cycles. Besides the isolation role of LSTP film, it is found that Ti 4+ ions in LSTP incorporate into the subsurface structure of NCA, which can accelerate the Li + diffusion, reduce the Li + /Ni 2+ disorder, reinforce the crystal structure, and enlarge the inter-slab spacing of NCA. Consequently, the coated NCA-2 %LSTP cathode reveals well structural integrity and evident phase transition behavior, delivering stable cycling performance with a superior capacity retention of 96.8 % at 1.0C after 100 cycles. This study not only deeply analyzes the mechanism of the structural degradation of NCA, but also demonstrates an efficient improving approach through LSTP modification.
研究领域:
材料科学
·
电化学
✓ 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
危险品化学品经营许可证（带存储）