共查询到20条相似文献，搜索用时 15 毫秒
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Evgeniya A. Saverina Roman R. Kapaev Dr. Pavel V. Stishenko Alexey S. Galushko Victoriya A. Balycheva Prof. Dr. Valentine P. Ananikov Prof. Dr. Mikhail P. Egorov Prof. Dr. Viatcheslav V. Jouikov Prof. Dr. Pavel A. Troshin Dr. Mikhail A. Syroeshkin 《ChemSusChem》2020,13(12):3137-3146
Various forms of germanium and germanium-containing compounds and materials are actively investigated as energy-intensive alternatives to graphite as the anode of lithium-ion batteries. The most accessible form—germanium dioxide—has the structure of a 3D polymer, which accounts for its rapid destruction during cycling, and requires the development of further approaches to the production of nanomaterials and various composites based on it. For the first time, we propose here the strategy of using 2-carboxyethylgermanium sesquioxide ([O1.5GeCH2CH2CO2H]n, 2-CEGS), in lieu of GeO2, as a promising, energy-intensive, and stable new source system for building lithium-ion anodes. Due to the presence of the organic substituent, the formed polymer has a 1D or a 2D space organization, which facilitates the reversible penetration of lithium into its structure. 2-CEGS is common and commercially available, completely safe and non-toxic, insoluble in organic solvents (which is important for battery use) but soluble in water (which is convenient for manufacturing diverse materials from it). This paper reports the preparation of micro- (flower-shaped agglomerates of ≈1 μm thick plates) and nanoformed (needle-shaped nanoparticles of ≈500×(50–80) nm) 2-CEGS using methods commonly available in laboratories and industry such as vacuum and freeze-drying of aqueous solutions of 2-CEGS. Lithium half-cell anodes based on 2-CEGS show a capacity of ≈400 mAh g−1 for microforms and up to ≈700 mAh g−1 for nanoforms, which is almost two times higher than the maximal theoretical capacity of graphite. These anodes are stable during the cycling at various rates. The results of DFT simulations suggest that Li atoms form the stable Li2O with the oxygen atoms of 2-CEGS, and actual charge–discharge cycles involve deoxygenated GeC3H5 molecules. Thus, C3 chains loosen the anode structure compared to pure Ge, improving its ability to accommodate Li ions. 相似文献
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Lithium‐ion batteries (LIBs) represent the state‐of‐the‐art technology in rechargeable energy‐storage devices and they currently occupy the prime position in the marketplace for powering an increasingly diverse range of applications. However, the fast development of these applications has led to increasing demands being placed on advanced LIBs in terms of higher energy/power densities and longer life cycles. For LIBs to meet these requirements, researchers have focused on active electrode materials, owing to their crucial roles in the electrochemical performance of batteries. For anode materials, compounds based on Group IVA (Si, Ge, and Sn) elements represent one of the directions in the development of high‐capacity anodes. Although these compounds have many significant advantages when used as anode materials for LIBs, there are still some critical problems to be solved before they can meet the high requirements for practical applications. In this Focus Review, we summarize a series of rational designs for Group IVA‐based anode materials, in terms of their chemical compositions and structures, that could address these problems, that is, huge volume variations during cycling, unstable surfaces/interfaces, and invalidation of transport pathways for electrons upon cycling. These designs should at least include one of the following structural benefits: 1) Contain a sufficient number of voids to accommodate the volume variations during cycling; 2) adopt a “plum‐pudding”‐like structure to limit the volume variations during cycling; 3) facilitate an efficient and permanent transport pathway for electrons and lithium ions; or 4) show stable surfaces/interfaces to stabilize the in situ formed SEI layers. 相似文献
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Germanium Quantum Dots Embedded in N‐Doping Graphene Matrix with Sponge‐Like Architecture for Enhanced Performance in Lithium‐Ion Batteries 
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下载免费PDF全文 Jinwen Qin Xia Wang Prof. Dr. Minhua Cao Changwen Hu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(31):9675-9682
Germanium quantum dots embedded in a nitrogen‐doped graphene matrix with a sponge‐like architecture (Ge/GN sponge) are prepared through a simple and scalable synthetic method, involving freeze drying to obtain the Ge(OH)4/graphene oxide (GO) precursor and subsequent heat reduction treatment. Upon application as an anode for the lithium‐ion battery (LIB), the Ge/GN sponge exhibits a high discharge capacity compared with previously reported N‐doped graphene. The electrode with the as‐synthesized Ge/GN sponge can deliver a capacity of 1258 mAh g?1 even after 50 charge/discharge cycles. This improved electrochemical performance can be attributed to the pore memory effect and highly conductive N‐doping GN matrix from the unique sponge‐like structure. 相似文献
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An Interwoven Network of MnO2 Nanowires and Carbon Nanotubes as the Anode for Bendable Lithium‐Ion Batteries 下载免费PDF全文
下载免费PDF全文 Shu Jing Ee Dr. Hongchang Pang Dr. Ulaganathan Mani Assoc. Prof. Qingyu Yan Siong Luong Ting Assoc. Prof. Peng Chen 《Chemphyschem》2014,15(12):2445-2449
A porous interwoven network is synthesized, consisting of ultralong MnO2 nanowires and multi‐walled carbon nanotubes (MWCNTs). Serving as the anode for a lithium‐ion battery, this nanocomposite demonstrates excellent performance due to the synergistic integration of these two 1D materials. Taking advantage of the excellent flexibility and strength of this MnO2–MWCNT network, a full, bendable battery is made that offers high capacity, cycling stability, and low cost. 相似文献
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Shang Chen Kangjia Tao Xin Chen Yongqiang Meng Manyun Wang Ji Zhou Chao Chen Yulin Wang Dr. Kwun Nam Hui Prof. Christopher W. Bielawski Prof. Jianxin Geng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(63):15706-15715
Lithium (Li) metal is regarded as the ultimate anode material for use in Li batteries due to its high theoretical capacity (3860 mA h g−1). However, the Li dendrites that are generated during iterative Li plating/stripping cycles cause poor cycling stability and even present safety risks, and thus severely handicap the commercial utility of Li metal anodes. Herein, we describe a graphene and carbon nanotube (CNT)-based Li host material that features vertically aligned channels with attached ZnO particles (designated ZnO@G-CNT-C) and show that the material effectively regulates Li plating and stripping. ZnO@G-CNT-C is prepared from an aqueous suspension of Zn(OAc)2, CNTs, and graphene oxide by using ice to template channel growth. ZnO@G-CNT-C was found to be mechanically robust and capable of guiding Li deposition on the inner walls of the channels without the formation of Li dendrites. When used as an electrode, the material exhibits relatively low polarization for Li plating, fast Li-ion diffusion, and high Coulombic efficiency, even over hundreds of Li plating/stripping cycles. Moreover, full cells prepared with ZnO@G-CNT-C as Li host and LiFePO4 as cathode exhibit outstanding performance in terms of specific capacity (155.9 mA h g−1 at 0.5 C), rate performance (91.8 mA h g−1 at 4 C), cycling stability (109.4 mA h g−1 at 0.5 C after 800 cycles). The methodology described can be readily adapted to enable the use of carbon-based electrodes with well-defined channels in a wide range of contemporary applications that pertain to energy storage and delivery. 相似文献
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Dr. Hao Wu Wenjun Liu Lihua Zheng Danfeng Zhu Dr. Ning Du Dr. Chengmao Xiao Dr. Liwei Su Prof. Lianbang Wang 《ChemistryOpen》2019,8(3):298-303
In this work, we introduce Ni nanopyramid arrays (NPAs) supported amorphous Ge anode architecture and demonstrate its effective improvement in sodium storage properties. The Ni−Ge NPAs are prepared by facile electrodeposition and sputtering method, which eliminates the need for any binder or conductive additive when used as a Na-ion battery anode. The electrodes display stable cycling performance and enhanced rate capabilities in contrast with planar Ge electrodes, which can be owing to the rational design of the architectured electrodes and firm bonding between current collector and active material (i. e. Ni and Ge, respectively). To validate improvement of nanostructures on electrochemical performance, sodium insertion behavior of crystalline Ge derived from Mg2Ge precursor has been investigated, in which limited but effective enhancement of sodium storage properties are realized by introducing porous nanostructure in crystalline Ge. These results show that elaborately designed configuration of Ge electrodes may be a promising anode for Na-ion battery applications. 相似文献
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采用超声波混合、抽滤的方法把多壁碳纳米管（MWCNTs）和乙炔黑混合制备了锂离子电池用复合导电剂浆料，用扫描电子显微镜（SEM）和恒流充放电测试考察了复合导电剂的结构和其作为导电剂对LiCoO2电极放电比容量的影响。SEM的分析结果表明MWCNTs和乙炔黑实现了纳米层次的均匀混合。复合导电剂悬浮液和浆料分别被用作导电剂制成了两种LiCoO2电极，前一种电极为Cathode A，后一种电极为Cathode B，考察了不同MWCNTs含量时，两种电极0．5C第10次放电比容量的差异。实验结果表明，随着MWCNTs含量的增加，两种电极放电比容量的差值增大，说明低含量MWCNTs的复合导电剂浆料是一种理想的锂离子电池导电剂。 相似文献
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The layered compounds LiCoO2, LiNiO2 and spinel compound LiMn2O4 have served as very effective cathode active materials in lithium ion rechargeable batteries. Generally, their high conductive resistance easily results in a serious polarization and poor utilization of active materials.In order to make full use of the active materials and increase the capacity, the charge-discharge rate and the cycle life of lithium ion batteries, conductive additives are often added into the above cathode materials to form a conductive network. Carbon materials, such as carbon black, graphite powders and chemical vapor deposit carbon fibers have been widely used as conductive additives owing to their high electrical conductivity and chemical inertness. To effectively utilize the active materials, the contents of these carbon additives in the cathode often reach up to 10～20wt%. This leads to a great need for binder, for example, 10wt% or more. It follows therefore a considerable increase in volume of the lithium batteries and lower energy density because of the large amount of carbon additives and binder in the cathode.By substituting carbon nanotubes (CNTs) for carbon black, graphite powders or chemical vapor deposit carbon fibers, much conductive additives and binder are saved, and the cathode with only 3～5wt% of conductive additives CNTs shows excellent rate capacity. At the discharge rate 0.5C,2.0C and 3.0C, the LiCoO2 cathode with CNTs exhibits discharge capacity up to 134mAh/g, 126 and 120mAh/g, respectively. The explanation is given as follows. Firstly, their microstructure and graphitic crystallinity are very important for electron transport. CNTs employed in the experiments comprise an array of complete graphite sheets seamlessly wrapped into cylindrical tubes which are concentrically nested like the rings of a tree trunk. Thus, the process of -electrons transport occurs in graphite sheet in super-conjugative manner when they move from one end to the other end in CNTs. Apparently, the CNTs' microstructure does good to electron transport. On the other hand,being highly graphitic (concluded from XRD patterns), CNTs also displays high electron conductivity. Secondly, being smaller in diameter, CNTs possess much larger number of primary particles in unit mass than other carbon materials. Hence, it results in a lower percolation threshold in the case of CNTs. Finally, owing to their high surface energy, CNTs fallen into nano-materials tend to aggregate and then form firm webs effectively entrapping LiCoO2 particles during the preparation of the cathode to guarantee their close contact with the active materials.Accordingly, effective electron channels are provided to lessen the polarization loss. 相似文献
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The current Highlight emphasizes the significance of a recently published Nature paper (Nature 2019 , 572, 511–515) and sheds light onto future research activities on Li anodes, for example, the solid electrolyte interphase Li, the dead Li, the morphology of the electrodeposited Li, as well as the correlation between the dead Li and battery performance degradation. 相似文献
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Xiaofeng He Xiao Liu Qing Han Peng Zhang Xiaosheng Song Yong Zhao 《Angewandte Chemie (International ed. in English)》2020,59(16):6397-6405
A proof‐of‐concept study on a liquid/liquid (L/L) two‐phase electrolyte interface is reported by using the polarity difference of solvent for the protection of Li‐metal anode with long‐term operation over 2000 h. The L/L electrolyte interface constructed by non‐polar fluorosilicane (PFTOS) and conventionally polar dimethyl sulfoxide solvents can block direct contact between conventional electrolyte and Li anode, and consequently their side reactions can be significantly eliminated. Moreover, the homogeneous Li‐ion flow and Li‐mass deposition can be realized by the formation of a thin and uniform solid‐electrolyte interphase (SEI) composed of LiF, LixC, LixSiOy between PFTOS and Li anode, as well as the super‐wettability state of PFTOS to Li anode, resulting in the suppression of Li dendrite formation. The cycling stability in a lithium–oxygen battery as a model is improved 4 times with the L/L electrolyte interface. 相似文献
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Lithium metal has been considered as the most promising anode electrode for substantially improving the energy density of next‐generation energy storage devices. However, uncontrollable lithium dendrite growth, an unstable solid electrolyte interface (SEI), and infinite volume variation severely shortens its service lifespan and causes safety hazards, thus hindering the practical application of lithium metal electrodes. Here, carbon fiber film (CFF) modified by lithiophilic Co3O4 nanowires (denoted as Co3O4 Nws) was proposed as a matrix for prestoring lithium metal through a thermal infusion method. The homogeneous needle‐like Co3O4 nanowires can effectively promote molten lithium to infiltrate into the CFF skeleton. The post‐formed Co?Li2O nanowires produced by the reaction of Co3O4 Nws and molten lithium can homogeneously distribute lithium ions flux and efficaciously increase the adsorption energy with lithium ions proved by density functional theory (DFT) calculation, boosting a uniform lithium deposition without dendrite growth. Therefore, the obtained composite anode (denoted as CFF/Co?Li2O@Li) exhibits superior electrochemical performance with high stripping/plating capacities of 3 mAh cm?2 and 5 mAh cm?2 over long‐term cycles in symmetrical batteries. Moreover, in comparison with bare lithium anode, superior Coulombic efficiencies coupled with copper collector and full battery behaviors paired with LiFePO4 cathode are achieved when CFF/Co?Li2O@Li composite anode was employed. 相似文献
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Falk Ebeler Dr. Yury V. Vishnevskiy Beate Neumann Dr. Hans-Georg Stammler Priv.-Doz. Dr. Rajendra S. Ghadwal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(31):e202200739
Mesoionic dithiolates [(MIDtAr)Li(LiBr)2(THF)3] (MIDtAr={SC(NDipp)}2CAr; Dipp=2,6-iPr2C6H3; Ar=Ph 3 a , 3-MeC6H4 (3-Tol) 3 b , 4-Me2NC6H4 (DMP) 3 c ) and [(MIDtPh)Li(THF)2] ( 4 ) are readily accessible (in≥90 % yields) as crystalline solids on treatments of anionic dicarbenes Li(ADCAr) ( 2 a - c ) (ADCAr={C(NDipp)2}2CAr) with elemental sulfur. 3 a - c and 4 are monoanionic ditopic ligands with both the sulfur atoms formally negatively charged, while the 1,3-imidazole unit bears a formal positive charge. Treatment of 4 with (L)GeCl2 (L=1,4-dioxane) affords the germylene (MIDtPh)GeCl ( 5 ) featuring a three-coordinated Ge atom. 5 reacts with (L)GeCl2 to give the Ge−Ge catenation product (MIDtPh)GeGeCl3 ( 6 ). KC8 reduction of 5 yields the homoleptic germylene (MIDtPh)2Ge ( 7 ). Compounds 3 a - c and 4 – 7 have been characterized by spectroscopic studies and single-crystal X-ray diffraction. The electronic structures of 4 – 7 have been analyzed by DFT calculations. 相似文献