共查询到20条相似文献,搜索用时 15 毫秒
1.
Juliette Billaud Christopher Eames Nuria Tapia‐Ruiz Matthew R. Roberts Andrew J. Naylor A. Robert Armstrong M. Saiful Islam Peter G. Bruce 《Liver Transplantation》2017,7(11)
The silicate compounds Li2MSiO4 (where M = Mn, Fe, Co) have received significant attention recently as Li intercalation electrodes. Overwhelmingly they exhibit relatively poor kinetics of ion intercalation. By synthesizing Li‐rich solid solutions of the form Li2+2x Fe1?x SiO4 (with 0 ≤ x ≤ 0.3), the structural requirements for fast ion transport and hence relatively fast intercalation have been identified. Specifically the presence of additional Li+ in interstitial sites, not normally occupied in the stoichiometric Li2FeSiO4 compound, enhances ion transport by more than two orders of magnitude. The results, obtained by combining electrochemical measurements, with powder X‐ray and neutron diffraction and atomistic modeling of the ion dynamics, provide valuable guidance in designing future intercalation electrodes with high Li‐ion transport and, hence, fast electrode kinetics. 相似文献
2.
Polysulfide‐Shuttle Control in Lithium‐Sulfur Batteries with a Chemically/Electrochemically Compatible NaSICON‐Type Solid Electrolyte
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A NaSICON‐type Li+‐ion conductive membrane with a formula of Li1+ x Y x Zr2? x (PO4)3 (LYZP) (x = 0–0.15) has been explored as a solid‐electrolyte/separator to suppress polysulfide‐crossover in lithium‐sulfur (Li‐S) batteries. The LYZP membrane with a reasonable Li+‐ion conductivity shows both favorable chemical compatibility with the lithium polysulfide species and exhibits good electrochemical stability under the operating conditions of the Li‐S batteries. Through an integration of the LYZP solid electrolyte with the liquid electrolyte, the hybrid Li‐S batteries show greatly enhanced cyclability in contrast to the conventional Li‐S batteries with the porous polymer (e.g., Celgard) separator. At a rate of C/5, the hybrid Li ||LYZP|| Li2S6 batteries developed in this study (with a Li‐metal anode, a liquid/LYZP hybrid electrolyte, and a dissolved lithium polysulfide cathode) delivers an initial discharge capacity of ≈1000 mA h g?1 (based on the active sulfur material) and retains ≈90% of the initial capacity after 150 cycles with a low capacity fade‐rate of <0.07% per cycle. 相似文献
3.
Qinyi Qiu Yintu Liu Kaiyang Xia Teng Fang Junjie Yu Xinbing Zhao Tiejun Zhu 《Liver Transplantation》2019,9(11)
High thermoelectric figure of merit zT of ≈1.0 has been reported in both n‐ and p‐type (Hf,Zr)CoSb‐based half‐Heusler compounds, and further improvement of thermoelectric performance relies on the insightful understanding of electron and phonon transport mechanisms. In this work, the thermoelectric transport features are analyzed for (Hf0.3Zr0.7)1?xNbxCoSb (x = 0.02–0.3) with a wide range of carrier concentration. It is found that, although both temperature and energy dependencies of charge transport resemble ionized impurity scattering, the grain boundary scattering is the dominant scattering mechanism near room temperature. With increasing carrier concentration and grain size, the influence of the grain boundary scattering on electron transport weakens. The dominant scattering mechanism changes from grain boundary scattering to acoustic phonon scattering as temperature rises. The lattice thermal conductivity decreases with increasing Nb doping content due to the increased strain field fluctuations. These results provide an in‐depth understanding of the transport mechanisms and guidance for further optimizing thermoelectric properties of half‐Heusler alloys and other thermoelectric systems. 相似文献
4.
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
5.
Iñigo Garbayo Michal Struzik William J. Bowman Reto Pfenninger Evelyn Stilp Jennifer L. M. Rupp 《Liver Transplantation》2018,8(12)
Ceramic Li7La3Zr2O12 garnet materials are promising candidates for the electrolytes in solid state batteries due to their high conductivity and structural stability. In this paper, the existence of “polyamorphism” leading to various glass‐type phases for Li‐garnet structure besides the known crystalline ceramic ones is demonstrated. A maximum in Li‐conductivity exists depending on a frozen thermodynamic glass state, as exemplified for thin film processing, for which the local near range order and bonding unit arrangement differ. Through processing temperature change, the crystallization and evolution through various amorphous and biphasic amorphous/crystalline phase states can be followed for constant Li‐total concentration up to fully crystalline nanostructures. These findings reveal that glass‐type thin film Li‐garnet conductors exist for which polyamorphism can be used to tune the Li‐conductivity being potential new solid state electrolyte phases to avoid Li‐dendrite formation (no grain boundaries) for future microbatteries and large‐scale solid state batteries. 相似文献
6.
Protons Enhance Conductivities in Lithium Halide Hydroxide/Lithium Oxyhalide Solid Electrolytes by Forming Rotating Hydroxy Groups
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Ah‐Young Song Yiran Xiao Kostiantyn Turcheniuk Punith Upadhya Anirudh Ramanujapuram Jim Benson Alexandre Magasinski Marco Olguin Lamartine Meda Oleg Borodin Gleb Yushin 《Liver Transplantation》2018,8(3)
Li‐halide hydroxides (Li2OHX) and Li‐oxyhalides (Li3OX) have emerged as new classes of low‐cost, lightweight solid state electrolytes (SSE) showing promising Li‐ion conductivities. The similarity in the lattice parameters between them, careless synthesis, and insufficient rigor in characterization often lead to erroneous interpretations of their compositions. Finally, moisture remaining in the synthesis or cell assembling environment and variability in the equivalent circuit models additionally contribute to significant errors in their properties. Thus, there remains a controversy about the real values of Li‐ion conductivities in such SSEs. Here an ultra‐fast synthesis and comprehensive material characterization is utilized to report on the ionic conductivities of contaminant‐free Li2+xOH1?xCl (x=0‐0.7), and Li2OHBr not exceeding 10‐4 S cm‐1 at 110 °C. Using powerful combination of experimental and numerical approaches, it is demonstrated that the presence of H in these SSEs yields significantly higher Li+ ‐ionic conductivity. Born‐Oppenheimer molecular dynamics simulations show excellent agreement with experimental results and reveal an unexpected mechanism for faster Li+ transport. It involves rotation of a short OH‐group in SSEs, which opens lower‐energy pathways for the formation of Frenkel defects and highly‐correlated Li+ jumps. These findings will reduce the existing confusions and show new avenues for tuning SSE compositions for further improved Li‐ion conductivities. 相似文献
7.
Structural and Chemical Evolution of the Layered Li‐Excess LixMnO3 as a Function of Li Content from First‐Principles Calculations
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Li2MnO3 is a critical component in the family of “Li‐excess” materials, which are attracting attention as advanced cathode materials for Li‐ion batteries. Here, first‐principle calculations are presented to investigate the electrochemical activity and structural stability of stoichiometric LixMnO3 (0 ≤ x ≤ 2) as a function of Li content. The Li2MnO3 structure is electrochemically activated above 4.5 V on delithiation and charge neutrality in the bulk of the material is mainly maintained by the oxidization of a portion of the oxygen ions from O2? to O1?. While oxygen vacancy formation is found to be thermodynamically favorable for x < 1, the activation barriers for O2? and O1? migration remain high throughout the Li composition range, impeding oxygen release from the bulk of the compound. Defect layered structures become thermodynamically favorable at lower Li content (x < 1), indicating a tendency towards the spinel‐like structure transformation. A critical phase transformation path for forming nuclei of spinel‐like domains within the matrix of the original layered structure is proposed. Formation of defect layered structures during the first charge is shown to manifest in a depression of the voltage profile on the first discharge, providing one possible explanation for the observed voltage fade of the Li‐excess materials. 相似文献
8.
Nagaphani B. Aetukuri Shintaro Kitajima Edward Jung Leslie E. Thompson Kumar Virwani Maria‐Louisa Reich Miriam Kunze Meike Schneider Wolfgang Schmidbauer Winfried W. Wilcke Donald S. Bethune J. Campbell Scott Robert D. Miller Ho‐Cheol Kim 《Liver Transplantation》2015,5(14)
The use of metallic lithium anodes enables higher energy density and higher specific capacity Li‐based batteries. However, it is essential to suppress lithium dendrite growth during electrodeposition. Li‐ion‐conducting ceramics (LICC) can mechanically suppress dendritic growth but are too fragile and also have low Li‐ion conductivity. Here, a simple, versatile, and scalable procedure for fabricating flexible Li‐ion‐conducting composite membranes composed of a single layer of LICC particles firmly embedded in a polymer matrix with their top and bottom surfaces exposed to allow for ionic transport is described. The membranes are thin (<100 μm) and possess high Li‐ion conductance at thicknesses where LICC disks are mechanically unstable. It is demonstrated that these membranes suppress Li dendrite growth even when the shear modulus of the matrix is lower than that of lithium. It is anticipated that these membranes enable the use of metallic lithium anodes in conventional and solid‐state Li‐ion batteries as well as in future Li? S and Li? O2 batteries. 相似文献
9.
Approaching the Minimum Thermal Conductivity in Rhenium‐Substituted Higher Manganese Silicides
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Xi Chen Steven N. Girard Fei Meng Edgar Lara‐Curzio Song Jin John B. Goodenough Jianshi Zhou Li Shi 《Liver Transplantation》2014,4(14)
Higher manganese silicides (HMS) made of earth‐abundant and non‐toxic elements are regarded as promising p‐type thermoelectric materials because their complex crystal structure results in low lattice thermal conductivity. It is shown here that the already low thermal conductivity of HMS can be reduced further to approach the minimum thermal conductivity via partial substitution of Mn with heavier rhenium (Re) to increase point defect scattering. The solubility limit of Re in the obtained RexMn1‐xSi1.8 is determined to be about x = 0.18. Elemental inhomogeneity and the formation of ReSi1.75 inclusions with 50?200 nm size are found within the HMS matrix. It is found that the power factor does not change markedly at low Re content of x ≤ 0.04 before it drops considerably at higher Re contents. Compared to pure HMS, the reduced lattice thermal conductivity in RexMn1‐xSi1.8 results in a 25% increase of the peak figure of merit ZT to reach 0.57 ± 0.08 at 800 K for x = 0.04. The suppressed thermal conductivity in the pure RexMn1‐xSi1.8 can enable further investigations of the ZT limit of this system by exploring different impurity doping strategies to optimize the carrier concentration and power factor. 相似文献
10.
Ah‐Young Song Kostiantyn Turcheniuk Johannes Leisen Yiran Xiao Lamartine Meda Oleg Borodin Gleb Yushin 《Liver Transplantation》2020,10(8)
Low‐melting‐point solid‐state electrolytes (SSE) are critically important for low‐cost manufacturing of all‐solid‐state batteries. Lithium hydroxychloride (Li2OHCl) is a promising material within the SSE domain due to its low melting point (mp < 300 °C), cheap ingredients (Li, H, O, and Cl), and rapid synthesis. Another unique feature of this compound is the presence of Li vacancies and rotating hydroxyl groups which promote Li‐ion diffusion, yet the role of the protons in the ion transport remains poorly understood. To examine lithium and proton dynamics, a set of solid‐state NMR experiments are conducted, such as magic‐angle spinning 7Li NMR, static 7Li and 1H NMR, and spin‐lattice T1(7Li)/T1(1H) relaxation experiments. It is determined that only Li+ contributes to long‐range ion transport, while H+ dynamics is constrained to an incomplete isotropic rotation of the OH group. The results uncover detailed mechanistic understanding of the ion transport in Li2OHCl. It is shown that two distinct phases of ionic motions appear at low and elevated temperatures, and that the rotation of the OH group controls Li+ and H+ dynamics in both phases. The model based on the NMR experiments is fully consistent with crystallographic information, ionic conductivity measurements, and Born–Oppenheimer molecular dynamic simulations. 相似文献
11.
Site‐Selective In Situ Electrochemical Doping for Mn‐Rich Layered Oxide Cathode Materials in Lithium‐Ion Batteries
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Aram Choi Jungwoo Lim Hyung‐Jin Kim Sung Chul Jung Hyung‐Woo Lim Hanseul Kim Mi‐Sook Kwon Young Kyu Han Seung M. Oh Kyu Tae Lee 《Liver Transplantation》2018,8(11)
Various doped materials have been investigated to improve the structural stability of layered transition metal oxides for lithium‐ion batteries. Most doped materials are obtained through solid state methods, in which the doping of cations is not strictly site selective. This paper demonstrates, for the first time, an in situ electrochemical site‐selective doping process that selectively substitutes Li+ at Li sites in Mn‐rich layered oxides with Mg2+. Mg2+ cations are electrochemically intercalated into Li sites in delithiated Mn‐rich layered oxides, resulting in the formation of [Li1?xMgy][Mn1?zMz]O2 (M = Co and Ni). This Mg2+ intercalation is irreversible, leading to the favorable doping of Mg2+ at the Li sites. More interestingly, the amount of intercalated Mg2+ dopants increases with the increasing amount of Mn in Li1?x[Mn1?zMz]O2, which is attributed to the fact that the Mn‐to‐O electron transfer enhances the attractive interaction between Mg2+ dopants and electronegative Oδ? atoms. Moreover, Mg2+ at the Li sites in layered oxides suppresses cation mixing during cycling, resulting in markedly improved capacity retention over 200 cycles. The first‐principle calculations further clarify the role of Mg2+ in reduced cation mixing during cycling. The new concept of in situ electrochemical doping provides a new avenue for the development of various selectively doped materials. 相似文献
12.
Yuankun Wang Ruifang Zhang Jie Chen Hu Wu Shiyao Lu Ke Wang Huanglong Li Christopher J. Harris Kai Xi Ramachandran Vasant Kumar Shujiang Ding 《Liver Transplantation》2019,9(24)
The altering of electronic states of metal oxides offers a promising opportunity to realize high‐efficiency surface catalysis, which play a key role in regulating polysulfides (PS) redox in lithium–sulfur (Li–S) batteries. However, little effort has been devoted to understanding the relationship between the electronic state of metal oxides and a catalyst's properties in Li–S cells. Herein, defect‐rich heterojunction electrocatalysts composed of ultrathin TiO2‐x nanosheets and carbon nanotubes (CNTs) for Li–S batteries are reported. Theoretical simulations indicate that oxygen vacancies and heterojunction can enhance electronic conductivity and chemical adsorption. Spectroscopy and electrochemical techniques further indicate that the rich surface vacancies in TiO2‐x nanosheets result in highly activated trapping sites for LiPS and lower energy barriers for fast Li ion mobility. Meanwhile, the redistribution of electrons at the heterojunction interfaces realizes accelerated surface electron exchange. Coupled with a polyacrylate terpolymer (LA132) binder, the CNT@TiO2‐x–S electrodes exhibit a long cycle life of more than 300 cycles at 1 C and a high area capacity of 5.4 mAh cm?2. This work offers a new perspective on understanding catalyst design in energy storage devices through band engineering. 相似文献
13.
Zhengyan Lun Bin Ouyang Daniil A. Kitchaev Raphaële J. Clment Joseph K. Papp Mahalingam Balasubramanian Yaosen Tian Teng Lei Tan Shi Bryan D. McCloskey Jinhyuk Lee Gerbrand Ceder 《Liver Transplantation》2019,9(2)
The recent discovery of Li‐excess cation‐disordered rock salt cathodes has greatly enlarged the design space of Li‐ion cathode materials. Evidence of facile lattice fluorine substitution for oxygen has further provided an important strategy to enhance the cycling performance of this class of materials. Here, a group of Mn3+–Nb5+‐based cation‐disordered oxyfluorides, Li1.2Mn3+0.6+0.5xNb5+0.2?0.5xO2?xFx (x = 0, 0.05, 0.1, 0.15, 0.2) is investigated and it is found that fluorination improves capacity retention in a very significant way. Combining spectroscopic methods and ab initio calculations, it is demonstrated that the increased transition‐metal redox (Mn3+/Mn4+) capacity that can be accommodated upon fluorination reduces reliance on oxygen redox and leads to less oxygen loss, as evidenced by differential electrochemical mass spectroscopy measurements. Furthermore, it is found that fluorine substitution also decreases the Mn3+‐induced Jahn–Teller distortion, leading to an orbital rearrangement that further increases the contribution of Mn‐redox capacity to the overall capacity. 相似文献
14.
Zongwei Zhang Yirui Yan Xiaofang Li Xinyu Wang Juan Li Chen Chen Feng Cao Jiehe Sui Xi Lin Xingjun Liu Guoqiang Xie Qian Zhang 《Liver Transplantation》2020,10(29)
1‐2‐2‐type Zintl phase compounds have promising thermoelectric properties because of their complex crystal structures and multiple valence‐band structures. In this work, a series of single phase (Yb0.9Mg0.1)MgxZn2?xSb2 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) compounds are prepared by alloying YbZn2Sb2 with 10 at% MgZn2Sb2 and different amounts of YbMg2Sb2. The incorporation of Mg at the Yb site, as well as at the Zn site, not only leads to an effective orbital alignment confirmed by the dramatically enhanced density of states effective mass and Seebeck coefficients, but also increases the point defect scattering, contributing to a low lattice thermal conductivity ≈0.54 W m?1 K?1 at 773 K. Combined with the optimization of the carrier concentration by Ag doping at the Zn site, a highest ZT value ≈1.5 at 773 K is achieved in (Yb0.9Mg0.1)Mg0.8Zn1.2Ag0.002Sb2, which is higher than that of all the previously reported 1‐2‐2‐type Zintl phase compounds. 相似文献
15.
Integrating Band Structure Engineering with All‐Scale Hierarchical Structuring for High Thermoelectric Performance in PbTe System
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Yanling Pei Gangjian Tan Dan Feng Lei Zheng Qing Tan Xiaobing Xie Shengkai Gong Yue Chen Jing‐Feng Li Jiaqing He Mercouri G. Kanatzidis Li‐Dong Zhao 《Liver Transplantation》2017,7(3)
PbTe1?x Sex ‐2%Na‐y%SrTe system is investigated and a high maximum ZT of 2.3 at 923 K for PbTe0.85Se0.15‐2%Na‐4%SrTe is reported. This is achieved by performing electronic band structures modifications as well as all‐scale hierarchical structuring and combining the two effects. It is found that high ZTs in PbTe0.85Se0.15‐2%Na‐4%SrTe are possible at all temperature from 300 to 873 K with an average ZTave of 1.23. The high performance in PbTe1?x Sex ‐2%Na‐y%SrTe can be achieved by either choosing PbTe‐2Na‐4SrTe or PbTe0.85Se0.15‐2Na as a matrix. At room temperature the carrier mobility shows negligible variations as SrTe fraction is increased, however the lattice thermal conductivity is significantly reduced from ≈1.1 to ≈0.82 W m?1 K?1 when 5.0% SrTe is added, correspondingly, the lattice thermal conductivity at 923 K decreases from ≈0.59 to ≈0.43 W m?1 K?1. The power factor maxima of PbTe1?x Sex ‐2Na‐4SrTe shift systematically to higher temperature with rising Se fractions due to bands divergence. The maximum power factors reach ≈27, ≈30, ≈31 μW cm?1 K?2 for the x = 0, 0.05, and 0.15 samples peak at 473, 573, and 623 K, respectively. The results indicate that ZT can be increased by synergistic integration of band structure engineering and all‐scale hierarchical architectures. 相似文献
16.
Feipeng Zhao Jianwen Liang Chuang Yu Qian Sun Xiaona Li Keegan Adair Changhong Wang Yang Zhao Shumin Zhang Weihan Li Sixu Deng Ruying Li Yining Huang Huan Huang Li Zhang Shangqian Zhao Shigang Lu Xueliang Sun 《Liver Transplantation》2020,10(9)
Sulfide‐based solid‐state electrolytes (SSEs) for all‐solid‐state Li metal batteries (ASSLMBs) are attracting significant attention due to their high ionic conductivity, inherently soft properties, and decent mechanical strength. However, the poor incompatibility with Li metal and air sensitivity have hindered their application. Herein, the Sn (IV) substitution for P (V) in argyrodite sulfide Li6PS5I (LPSI) SSEs is reported, in the preparation of novel LPSI‐xSn SSEs (where x is the Sn substitution percentage). Appropriate aliovalent element substitutions with larger atomic radius (R<Sn> > R<P>) provides the optimized LPSI‐20Sn electrolyte with a 125 times higher ionic conductivity compared to that of the LPSI electrolyte. The high ionic conductivity of LPSI‐20Sn enables the rich I‐containing electrolyte to serve as a stabilized interlayer against Li metal in sulfide‐based ASSLMBs with outstanding cycling stability and rate capability. Most importantly, benefiting from the strong Sn–S bonding in Sn‐substituted electrolytes, the LPSI‐20Sn electrolyte shows excellent structural stability and improved air stability after exposure to O2 and moisture. The versatile Sn substitution in argyrodite LPSI electrolytes is believed to provide a new and effective strategy to achieve Li metal‐compatible and air‐stable sulfide‐based SSEs for large‐scale applications. 相似文献
17.
Jianwen Liang Xiaona Li Yang Zhao Lyudmila V. Goncharova Weihan Li Keegan R. Adair Mohammad Norouzi Banis Yongfeng Hu Tsun‐Kong Sham Huan Huang Li Zhang Shangqian Zhao Shigang Lu Ruying Li Xueliang Sun 《Liver Transplantation》2019,9(38)
Li metal is a promising anode material for all‐solid‐state batteries, owing to its high specific capacity and low electrochemical potential. However, direct contact of Li metal with most solid‐state electrolytes induces severe side reactions that can lead to dendrite formation and short circuits. Moreover, Li metal is unstable when exposed to air, leading to stringent processing requirements. Herein, it is reported that the Li3PS4/Li interface in all‐solid‐state batteries can be stabilized by an air‐stable LixSiSy protection layer that is formed in situ on the surface of Li metal through a solution‐based method. Highly stable Li cycling for over 2000 h in symmetrical cells and a lifetime of over 100 cycles can be achieved for an all‐solid‐state LiCoO2/Li3PS4/Li cell. Synchrotron‐based high energy X‐ray photoelectron spectroscopy in‐depth analysis demonstrates the distribution of different components within the protection layer. The in situ formation of an electronically insulating LixSiSy protection layer with highly ionic conductivity provides an effective way to prevent Li dendrite formation in high‐energy all‐solid‐state Li metal batteries. 相似文献
18.
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
19.
Yongli Song Luyi Yang Wenguang Zhao Zijian Wang Yan Zhao Ziqi Wang Qinghe Zhao Hao Liu Feng Pan 《Liver Transplantation》2019,9(21)
Garnet‐type solid‐state electrolytes (SSEs) have been widely studied as a promising candidate for Li metal batteries. Despite the common belief that inorganic SSEs can prevent dendrite propagation, garnet SSEs suffer from relatively low critical current density (CCD) at which the SSEs are abruptly short‐circuited by Li dendrites. In this study, the short‐circuiting mechanism of garnet Li7La2.75Ca0.25Zr1.75Nb0.25O12 (LLCZN) is investigated. It is found that instead of propagating uniaxially from one electrode to other in a dendritic form, metallic lithium is formed within the SSE. This can be attributed to the fact that electrons combine with Li ions at the grain boundary, which exhibits relatively high electronic conductivity, and then reduce Li+ to Li0 to cause short circuits. In order to reduce the electronic conductivity at the grain boundary, a thin layer of LiAlO2 is coated on the grain surface of LLCZN, which results in an improved CCD value. It is also found that under higher external voltages, the electronic conductivity of SSE becomes more significant, which is believed to be the origin of CCD. These findings not only shed light on the short‐circuiting mechanism of garnet‐type SSEs but also offer a novel perspective and useful guidance on their designs and modifications. 相似文献
20.
Zhipeng Li Li Wang Ranran Liu Yingping Fan Hongguang Meng Zhipeng Shao Guanglei Cui Shuping Pang 《Liver Transplantation》2019,9(38)
Interface engineering is of great concern in photovoltaic devices. For the solution‐processed perovskite solar cells, the modification of the bottom surface of the perovskite layer is a challenge due to solvent incompatibility. Herein, a Cl‐containing tin‐based electron transport layer; SnOx‐Cl, is designed to realize an in situ, spontaneous ion‐exchange reaction at the interface of SnOx‐Cl/MAPbI3. The interfacial ion rearrangement not only effectively passivates the physical contact defects, but, at the same time, the diffusion of Cl ions in the perovskite film also causes longitudinal grain growth and further reduces the grain boundary density. As a result, an efficiency of 20.32% is achieved with an extremely high open‐circuit voltage of 1.19 V. This versatile design of the underlying carrier transport layer provides a new way to improve the performance of perovskite solar cells and other optoelectronic devices. 相似文献