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1.
N‐Doped Graphene Modified 3D Porous Cu Current Collector toward Microscale Homogeneous Li Deposition for Li Metal Anodes
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Rui Zhang Shuaiwei Wen Ning Wang Kaiqiang Qin Enzuo Liu Chunsheng Shi Naiqin Zhao 《Liver Transplantation》2018,8(23)
Lithium metal is the most promising anode material for high‐energy‐density batteries due to its high specific capacity of 3860 mAh g?1 and low reduction potential of ?3.04 V versus standard hydrogen electrode. However, huge volume change, safety concerns, and low efficiency impede the practical applications of Li metal anodes. Herein, it is shown that the nitrogen‐doped graphene modified 3D porous Cu (3DCu@NG) current collector can mitigate the above problems. The N‐doped graphene, coating on the surface of 3D current collector, not only contributes to a uniform Li+ flux, but also leads to a scattered distribution of electrons throughout the surface, finally contributing to a uniform Li deposition and the improved electrochemical performance. In addition, the continuously porous structure of 3DCu@NG provides a space for the metallic Li deposition and could effectually accommodate the volume expansion during cycling. As a result, the Li‐3DCu@NG anode exhibits a high areal capacity of 4 mAh cm?2, a high Li utilization of ≈98%, and an ultralow voltage hysteresis of ≈19 mV. The multifunctional N‐doped graphene modified 3D porous current collector promisingly provides a strategy for safe and high‐energy lithium metal anodes. 相似文献
2.
Kuroda T Fujita N Utsugi J Kuroda M Mizushima T Tsuchiya T 《Microbiology and immunology》2004,48(4):243-250
A gene encoding a Li(+) extrusion system was cloned from the chromosomal DNA of Pseudomonas aeruginosa and expressed in Escherichia coli cells. The gene enabled growth of E. coli KNabc cells, which were unable to grow in the presence of 10 mM LiCl or 0.1 M NaCl because of the lack of major Na(+) (Li(+))/H(+) antiporters. We detected Li(+)/H(+) and Na(+)/H(+) antiport activities in membrane vesicles prepared from E. coli KNabc cells that harbored a plasmid carrying the cloned gene. Activity of this antiporter was pH-dependent with an optimal pH activity between pH 7.5 and 8.5. These properties indicate that this antiporter is different from NhaP, an Na(+)/H(+) antiporter from P. aeruginosa that we reported previously, and that is rather specific to Na(+) but it cannot extrude Li(+) effectively. The gene was sequenced and an open reading frame (ORF) was identified. The amino acid sequence deduced from the ORF showed homology (about 60% identity and 90% similarity) with that of the NhaB Na(+)/H(+) antiporters of E. coli and Vibrio parahaemolyticus. Thus, we designated the antiporter as NhaB of P. aeruginosa. E. coli KNabc carrying the nhaB gene from P. aeruginosa was able to grow in the presence of 10 to 50 mM LiCl, although KNabc carrying nhaP was unable to grow in these conditions. The antiport activity of NhaB from P. aeruginosa was produced in E. coli and showed apparent Km values for Li(+) and Na(+) of 2.0 mM and 1.3 mM, respectively. The antiport activity was inhibited by amiloride with a Ki value for Li(+) and Na(+) of 0.03 mM and 0.04 mM, respectively. 相似文献
3.
Jatinkumar Rana Marian Stan Richard Kloepsch Jie Li Gerhard Schumacher Edmund Welter Ivo Zizak John Banhart Martin Winter 《Liver Transplantation》2014,4(5)
Structural changes in Li2MnO3 cathode material for rechargeable Li‐ion batteries are investigated during the first and 33rd cycles. It is found that both the participation of oxygen anions in redox processes and Li+‐H+ exchange play an important role in the electrochemistry of Li2MnO3. During activation, oxygen removal from the material along with Li gives rise to the formation of a layered MnO2‐type structure, while the presence of protons in the interslab region, as a result of electrolyte oxidation and Li+‐H+ exchange, alters the stacking sequence of oxygen layers. Li re‐insertion by exchanging already present protons reverts the stacking sequence of oxygen layers. The re‐lithiated structure closely resembles the parent Li2MnO3, except that it contains less Li and O. Mn4+ ions remain electrochemically inactive at all times. Irreversible oxygen release occurs only during activation of the material in the first cycle. During subsequent cycles, electrochemical processes seem to involve unusual redox processes of oxygen anions of active material along with the repetitive, irreversible oxidation of electrolyte species. The deteriorating electrochemical performance of Li2MnO3 upon cycling is attributed to the structural degradation caused by repetitive shearing of oxygen layers. 相似文献
4.
Recently, a consensus has been reached that using lithium metal as an anode in rechargeable Li‐ion batteries is the best way to obtain the high energy density necessary to power electronic devices. Challenges remain, however, with respect to controlling dendritic Li growth on these electrodes, enhancing compatibility with carbonate‐based electrolytes, and forming a stable solid–electrolyte interface layer. Herein, a groundbreaking solution to these challenges consisting in the preparation of a Li2TiO3 (LT) layer that can be used to cover Li electrodes via a simple and scalable fabrication method, is suggested. Not only does this LT layer impede direct contact between electrode and electrolyte, thus avoiding side reactions, but it assists and expedites Li‐ion flux in batteries, thus suppressing Li dendrite growth. Other effects of the LT layer on electrochemical performance are investigated by scanning electron microscopy, electrochemical impedance spectroscopy, and galvanostatic intermittent titration technique analyses. Notably, LT layer‐incorporating Li cells comprising high‐capacity/voltage cathodes with reasonably high mass loading (LiNi0.8Co0.1Mn0.1O2, LiNi0.5Mn1.5O4, and LiMn2O4) show highly stable cycling performance in a carbonate‐based electrolyte. Therefore, it is believed that the approach based on the LT layer can boost the realization of high energy density lithium metal batteries and next‐generation batteries. 相似文献
5.
The formation of a solid‐electrolyte interphase on the anode surface of an Li‐ion battery using an organic liquid electrolyte robs Li+ irreversibly form the cathode on the initial charge if the cells are fabricated in the discharged state. In order to increase the cathode capacity, the use of Li3N as a sacrificial source of Li+ on the initial charge has been evaluated chemically and electrochemically as an additive to an LiCoO2 cathode. Li3N is shown to be chemically stable in a dry atmosphere as small particles with fresh surfaces and can increase the reversible capacities of a full cell without compromising the rate capability of the cells. 相似文献
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Direct Observation of Li‐Ion Transport in Electrodes under Nonequilibrium Conditions Using Neutron Depth Profiling
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One of the key challenges of Li‐ion electrodes is enhancement of (dis)charge rates. This is severely hindered by the absence of a technique that allows direct and nondestructive observation of lithium ions in operating batteries. Direct observation of the Li‐ion concentration profiles using operando neutron depth profiling reveals that the rate‐limiting step is depended not only on the electrode morphology but also on the cycling rate itself. In the LiFePO4 electrodes phase nucleation limits the charge transport at the lowest cycling rates, whereas electronic conductivity is rate limiting at intermediate rates, and only at the highest rates ionic transport through the electrode is rate limiting. These novel insights into electrode kinetics are imperative for the improvement of Li‐ion batteries and show the large value of in situ NDP in Li‐ion battery research and development. 相似文献
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Optimized Temperature Effect of Li‐Ion Diffusion with Layer Distance in Li(NixMnyCoz)O2 Cathode Materials for High Performance Li‐Ion Battery
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Suihan Cui Yi Wei Tongchao Liu Wenjun Deng Zongxiang Hu Yantao Su Hao Li Maofan Li Hua Guo Yandong Duan Weidong Wang Mumin Rao Jiaxin Zheng Xinwei Wang Feng Pan 《Liver Transplantation》2016,6(4)
Understanding and optimizing the temperature effects of Li‐ion diffusion by analyzing crystal structures of layered Li(NixMnyCoz)O2 (NMC) (x + y + z = 1) materials is important to develop advanced rechargeable Li‐ion batteries (LIBs) for multi‐temperature applications with high power density. Combined with experiments and ab initio calculations, the layer distances and kinetics of Li‐ion diffusion of LiNixMnyCozO2 (NMC) materials in different states of Li‐ion de‐intercalation and temperatures are investigated systematically. An improved model is also developed to reduce the system error of the “Galvanostatic Intermittent Titration Technique” with a correction of NMC particle size distribution. The Li‐ion diffusion coefficients of all the NMC materials are measured from ?25 to 50 °C. It is found that the Li‐ion diffusion coefficient of LiNi0.6Mn0.2Co0.2O2 is the largest with the minimum temperature effect. Ab initio calculations and XRD measurements indicate that the larger Li slab space benefits to Li‐ion diffusion with minimum temperature effect in layered NMC materials. 相似文献
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Zhidan Zeng Qingfeng Zeng Nian Liu Artem R. Oganov Qiaoshi Zeng Yi Cui Wendy L. Mao 《Liver Transplantation》2015,5(12)
Li15Si4, the only crystalline phase that forms during lithiation of the Si anode in lithium‐ion batteries, is found to undergo a structural transition to a new phase at 7 GPa. Despite the large unit cell of Li15Si4 (152 atoms in the unit cell), ab initio evolutionary metadynamics (using the USPEX code) successfully predicts the atomic structure of this new phase (β‐Li15Si4), which has an orthorhombic structure with an Fdd2 space group. In the new β‐Li15Si4 phase Si atoms are isolated by Li atoms analogous to the original cubic phase (α‐Li15Si4), whereas the atomic packing is more efficient owing to the higher Si? Li coordination number and shorter Si? Li, Li? Li bonds. β‐Li15Si4 has substantially larger elastic moduli compared with α‐Li15Si4, and has a good electrical conductivity. As a result, β‐Li15Si4 has superior resistance to deformation and fracture under stress. The theoretical volume expansion of Si would decrease 25% if it transforms to β‐Li15Si4, instead of α‐Li15Si4, during lithiation. Moreover, β‐Li15Si4 can be recovered back to ambient pressure, providing opportunities to further investigate its properties and potential applications. 相似文献
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SiO2 Hollow Nanosphere‐Based Composite Solid Electrolyte for Lithium Metal Batteries to Suppress Lithium Dendrite Growth and Enhance Cycle Life
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Dong Zhou Ruliang Liu Yan‐Bing He Fengyun Li Ming Liu Baohua Li Quan‐Hong Yang Qiang Cai Feiyu Kang 《Liver Transplantation》2016,6(7)
The low Coulombic efficiency and serious security issues of lithium (Li) metal anode caused by uncontrollable Li dendrite growth have permanently prevented its practical application. A novel SiO2 hollow nanosphere‐based composite solid electrolyte (SiSE) for Li metal batteries is reported. This hierarchical electrolyte is fabricated via in situ polymerizing the tripropylene gycol diacrylate (TPGDA) monomer in the presence of liquid electrolyte, which is absorbed in a SiO2 hollow nanosphere layer. The polymerized TPGDA framework keeps the prepared SiSE in a quasi‐solid state without safety risks caused by electrolyte leakage, meanwhile the SiO2 layer not only acts as a mechanics‐strong separator but also provides the SiSE with high room‐temperature ionic conductivity (1.74 × 10?3 S cm?1) due to the high pore volume (1.49 cm3 g?1) and large liquid electrolyte uptake of SiO2 hollow nanospheres. When the SiSE is in situ fabricated on the cathode and applied to LiFePO4/SiSE/Li batteries, the obtained cells show a significant improvement in cycling stability, mainly attributed to the stable electrode/electrolyte interface and remarkable suppression for Li dendrite growth by the SiSE. This work can extend the application of hollow nanooxide and enable a safe, efficient operation of Li anode in next generation energy storage systems. 相似文献
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A series of non‐aqueous electrolytes were prepared by dissolving lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) in triglyme and tetraglyme (Gx, x = 3 and 4), respectively, with varied molar ratios. With the electrolytes the cycling performance of Li‐O2 batteries showed a strong dependence on the molar ratios between LiTFSA and Gx. It was found that the molar ratio of 1 to 5 was critical for the cycling‐performance of Li‐O2 batteries. High stability over 20 discharge–recharge cycles at 500 mA/gcarbon and in an O2 flow was obtained in LiTFSA‐(Gx)5 (x = 3 and 4). The discharge product at cathode could be directly detected and identified as the dominant crystalline product Li2O2 on the 1st and 20th discharged electrodes using X‐ray diffraction technique (XRD), which indicates rechargeability and feasibility of the electrolytes LiTFSA‐(Gx)5 (x = 3 and 4) for Li‐O2 batteries. At 1000 mA/gcarbon their capacities could be stabilized for 10 cycles. To our knowledge, this behavior of dependence of cycling performance of Li‐O2 batteries on the concentration of Li salts is presented here for the first time, and it may be extended to other Li salts and solvents and suggest a new route for screening cycling‐stable electrolytes for Li‐O2 batteries. 相似文献
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Interface‐Engineered All‐Solid‐State Li‐Ion Batteries Based on Garnet‐Type Fast Li+ Conductors
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All‐solid‐state Li‐ion batteries based on Li7La3Zr2O12 (LLZO) garnet structures require novel electrode assembly strategies to guarantee a proper Li+ transfer at the electrode–electrolyte interfaces. Here, first stable cell performances are reported for Li‐garnet, c‐Li6.25Al0.25La3Zr2O12, all‐solid‐state batteries running safely with a full ceramics setup, exemplified with the anode material Li4Ti5O12. Novel strategies to design an enhanced Li+ transfer at the electrode–electrolyte interface using an interface‐engineered all‐solid‐state battery cell based on a porous garnet electrolyte interface structure, in which the electrode material is intimately embedded, are presented. The results presented here show for the first time that all‐solid‐state Li‐ion batteries with LLZO electrolytes can be reversibly charge–discharge cycled also in the low potential ranges (≈1.5 V) for combinations with a ceramic anode material. Through a model experiment, the interface between the electrode and electrolyte constituents is systematically modified revealing that the interface engineering helps to improve delivered capacities and cycling properties of the all‐solid‐state Li‐ion batteries based on garnet‐type cubic LLZO structures. 相似文献
17.
Ning Li Sooyeon Hwang Meiling Sun Yanbao Fu Vincent S. Battaglia Dong Su Wei Tong 《Liver Transplantation》2019,9(47)
Extensive efforts have been devoted to unraveling the true cause of voltage decay in Li, Mn‐rich layered oxides. An initial consensus was reached on structural rearrangement, then leaned toward the newly discovered lattice oxygen activity. It is challenging to differentiate their explicit roles because these events typically coexist during the electrochemical reaction of most Li‐rich layered oxides. Here, the voltage decay behavior is probed in Li1.2Ni0.2Ru0.6O2, a structurally and electrochemically relevant compound to Li, Mn‐rich layered oxide, but of no oxygen activity. Such intriguing characteristics allow the explicit decoupling of the contribution of transition metal migration and lattice oxygen activity to voltage decay in Li‐rich layered oxides. The results demonstrate that the microstructural evolution, mainly originating from transition metal migration, is a direct cause of voltage decay, and lattice oxygen activity likely accelerates the decay. 相似文献
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花生种子吸胀2d后,子叶中肽链内切酶活性上升,贮藏蛋白质开始降解。高活力种子肽链内切酶活性在吸胀2d后迅速上升,至4d时达到高峰,而中等活力种子的肽链内切酶活性上升速度绶慢。高活力种子萌发时贮藏蛋白质降解速度高于中等活力种子。中等活力种子经PEG和PUT处理可提高种子活力,也促进了种子贮藏蛋白质降解能力的提高。 相似文献
20.
Yanchen Liu Jing Wang Junwei Wu Zhiyu Ding Penghui Yao Sanli Zhang Yanan Chen 《Liver Transplantation》2020,10(5)
Li‐rich oxide is a promising candidate for the cathodes of next‐generation lithium‐ion batteries. However, its utilization is restricted by cycling instability and inferior rate capability. To tackle these issues, three‐dimensional (3D), hierarchical, cube‐maze‐like Li‐rich cathodes assembled from two‐dimensional (2D), thin nanosheets with exposed {010} active planes, are developed by a facile hydrothermal approach. Benefiting from their unique architecture, 3D cube‐maze‐like cathodes demonstrate a superior reversible capacity (285.3 mAh g?1 at 0.1 C, 133.4 mAh g?1 at 20.0 C) and a great cycle stability (capacity retention of 87.4% after 400 cycles at 2.0 C, 85.2% after 600 cycles and 75.0% after 1200 cycles at 20.0 C). When this material is matched with a graphite anode, the full cell achieves a remarkable discharge capacity (275.2 mAh g?1 at 0.1 C) and stable cycling behavior (capacity retention of 88.7% after 100 cycles at 5.0 C, capacity retention of 84.8% after 100 cycles at 20.0 C). The present work proposes an accessible way to construct 3D hierarchical architecture assembled from 2D nanosheets with exposed high‐energy active {010} planes and verifies its validity for advanced Li‐rich cathodes. 相似文献