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1.
Ascorbic Acid‐Assisted Synthesis of Mesoporous Sodium Vanadium Phosphate Nanoparticles with Highly sp2‐Coordinated Carbon Coatings as Efficient Cathode Materials for Rechargeable Sodium‐Ion Batteries 下载免费PDF全文
Dr. Tai‐Feng Hung Wei‐Jen Cheng Dr. Wen‐Sheng Chang Dr. Chang‐Chung Yang Dr. Chin‐Chang Shen Dr. Yu‐Lin Kuo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10620-10626
Herein, mesoporous sodium vanadium phosphate nanoparticles with highly sp2‐coordinated carbon coatings (meso‐Na3V2(PO4)3/C) were successfully synthesized as efficient cathode material for rechargeable sodium‐ion batteries by using ascorbic acid as both the reductant and carbon source, followed by calcination at 750 °C in an argon atmosphere. Their crystalline structure, morphology, surface area, chemical composition, carbon nature and amount were systematically explored. Following electrochemical measurements, the resultant meso‐Na3V2(PO4)3/C not only delivered good reversible capacity (98 mAh g?1 at 0.1 A g?1) and superior rate capability (63 mAh g?1 at 1 A g?1) but also exhibited comparable cycling performance (capacity retention: ≈74 % at 450 cycles at 0.4 A g?1). Moreover, the symmetrical sodium‐ion full cell with excellent reversibility and cycling stability was also achieved (capacity retention: 92.2 % at 0.1 A g?1 with 99.5 % coulombic efficiency after 100 cycles). These attributes are ascribed to the distinctive mesostructure for facile sodium‐ion insertion/extraction and their continuous sp2‐coordinated carbon coatings, which facilitate electronic conduction. 相似文献
2.
Dr. Anqiang Pan Ting Zhu Hao Bin Wu Prof. Xiong Wen Lou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(2):494-500
Nanosheet‐assembled hierarchical V2O5 hollow microspheres are successfully obtained from V‐glycolate precursor hollow microspheres, which in turn are synthesized by a simple template‐free solvothermal method. The structural evolution of the V‐glycolate hollow microspheres has been studied and explained by the inside‐out Ostwald‐ripening mechanism. The surface morphologies of the hollow microspheres can be controlled by varying the mixture solution and the solvothermal reaction time. After calcination in air, hierarchical V2O5 hollow microspheres with a high surface area of 70 m2 g?1 can be obtained and the structure is well preserved. When evaluated as cathode materials for lithium‐ion batteries, the as‐prepared hierarchical V2O5 hollow spheres deliver a specific discharge capacity of 144 mA h g?1 at a current density of 100 mA g?1, which is very close to the theoretical capacity (147 mA h g?1) for one Li+ insertion per V2O5. In addition, excellent rate capability and cycling stability are observed, suggesting their promising use in lithium‐ion batteries. 相似文献
3.
Xianghua Zhang Haoliang Chen Weiling Liu Ni Xiao Qi Zhang Xianhong Rui Shaoming Huang 《化学:亚洲杂志》2020,15(9):1430-1435
Aqueous zinc‐ion batteries (ZIBs) have become the highest potential energy storage system for large‐scale applications owing to the high specific capacity, good safety and low cost. In this work, a NASICON‐type Na3V2(PO4)3 cathode modified by a uniform carbon layer (NVP/C) has been synthesized via a facile solid‐state method and exhibited significantly improved electrochemical performance when working in an aqueous ZIB. Specifically, the NVP/C cathode shows an excellent rate capacity (e. g., 48 mAh g?1 at 1.0 A g?1). Good cycle stability is also achieved (e. g., showing a capacity retention of 88% after 2000 cycles at 1.0 A g?1). Furthermore, the Zn2+ (de)intercalation mechanism in the NVP cathode has been determined by various ex‐situ techniques. In addition, a Zn||NVP/C pouch cell has been assembled, delivering a high capacity of 89 mAhg?1 at 0.2 A g?1 and exhibiting a superior long cycling stability. 相似文献
4.
Tailored Organic Electrode Material Compatible with Sulfide Electrolyte for Stable All‐Solid‐State Sodium Batteries 下载免费PDF全文
Dr. Xiaowei Chi Dr. Yanliang Liang Fang Hao Ye Zhang Dr. Justin Whiteley Hui Dong Dr. Pu Hu Prof. Sehee Lee Prof. Yan Yao 《Angewandte Chemie (International ed. in English)》2018,57(10):2630-2634
All‐solid‐state sodium batteries (ASSSBs) with nonflammable electrolytes and ubiquitous sodium resource are a promising solution to the safety and cost concerns for lithium‐ion batteries. However, the intrinsic mismatch between low anodic decomposition potential of superionic sulfide electrolytes and high operating potentials of sodium‐ion cathodes leads to a volatile cathode–electrolyte interface and undesirable cell performance. Here we report a high‐capacity organic cathode, Na4C6O6, that is chemically and electrochemically compatible with sulfide electrolytes. A bulk‐type ASSSB shows high specific capacity (184 mAh g?1) and one of the highest specific energies (395 Wh kg?1) among intercalation compound‐based ASSSBs. The capacity retentions of 76 % after 100 cycles at 0.1 C and 70 % after 400 cycles at 0.2 C represent the record stability for ASSSBs. Additionally, Na4C6O6 functions as a capable anode material, enabling a symmetric all‐organic ASSSB with Na4C6O6 as both cathode and anode materials. 相似文献
5.
Wei Shen Cong Wang Prof. Dr. Haimei Liu Prof. Wensheng Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(43):14712-14718
A porous Na3V2(PO4)3 cathode material coated uniformly with a layer of approximately 6 nm carbon has been synthesized by the sol–gel method combined with a freeze‐drying process. The special porous morphology and structure significantly increases the specific surface area of the material, which greatly enlarges the contact area between the electrode and electrolyte, and consequently supplies more active sites for sodium ions. When employed as a cathode material of sodium‐ion batteries, this porous Na3V2(PO4)3/C exhibits excellent rate performance and cycling stability; for instance, it shows quite a flat potential plateau at 3.4 V in the potential window of 2.7–4.0 V versus Na+/Na and delivers an initial capacity as high as 118.9 and 98.0 mA h g?1 at current rates of 0.05 and 0.5 C, respectively, and after 50 cycles, a good capacity retention of 92.7 and 93.6 % are maintained. Moreover, even when the discharge current density is increased to 5 C (590 mA g?1), an initial capacity of 97.6 mA h g?1 can still be achieved, and an exciting capacity retention of 88.6 % is obtained after 100 cycles. The good cycle performance, excellent rate capability, and moreover, the low cost of Na3V2(PO4)3/C suggest that this material is a promising cathode for large‐scale sodium‐ion rechargeable batteries. 相似文献
6.
A Superior Na3V2(PO4)3‐Based Nanocomposite Enhanced by Both N‐Doped Coating Carbon and Graphene as the Cathode for Sodium‐Ion Batteries 下载免费PDF全文
Jin‐Zhi Guo Dr. Xing‐Long Wu Fang Wan Jie Wang Xiao‐Hua Zhang Prof. Rong‐Shun Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(48):17371-17378
A superior Na3V2(PO4)3‐based nanocomposite (NVP/C/rGO) has been successfully developed by a facile carbothermal reduction method using one most‐common chelator, disodium ethylenediamintetraacetate [Na2(C10H16N2O8)], as both sodium and nitrogen‐doped carbon sources for the first time. 2D‐reduced graphene oxide (rGO) nanosheets are also employed as highly conductive additives to facilitate the electrical conductivity and limit the growth of NVP nanoparticles. When used as the cathode material for sodium‐ion batteries, the NVP/C/rGO nanocomposite exhibits the highest discharge capacity, the best high‐rate capabilities and prolonged cycling life compared to the pristine NVP and single‐carbon‐modified NVP/C. Specifically, the 0.1 C discharge capacity delivered by the NVP/C/rGO is 116.8 mAh g?1, which is obviously higher than 106 and 112.3 mAh g?1 for the NVP/C and pristine NVP respectively; it can still deliver a specific capacity of about 80 mAh g?1 even at a high rate up to 30 C; and its capacity decay is as low as 0.0355 % per cycle when cycled at 0.2 C. Furthermore, the electrochemical impedance spectroscopy was also implemented to compare the electrode kinetics of all three NVP‐based cathodes including the apparent Na diffusion coefficients and charge‐transfer resistances. 相似文献
7.
Shaohua Guo Dr. Pan Liu Dr. Yang Sun Kai Zhu Dr. Jin Yi Prof. Mingwei Chen Prof. Masayoshi Ishida Prof. Haoshen Zhou 《Angewandte Chemie (International ed. in English)》2015,54(40):11701-11705
Recently, there has been great interest in developing advanced sodium‐ion batteries for large‐scale application. Most efforts have concentrated on the search for high‐performance electrode materials only in sodium half‐cells. Research on sodium full cells for practical application has encountered many problems, such as insufficient cycles with rapid capacity decay, low safety, and low operating voltage. Herein, we present a layered P2‐Na0.66Ni0.17Co0.17Ti0.66O2, as both an anode (ca. 0.69 V versus Na+/Na) and as a high‐voltage cathode (ca. 3.74 V versus Na+/Na). The full cell based on this bipolar electrode exhibits well‐defined voltage plateaus near 3.10 V, which is the highest average voltage in the symmetric cells. It also shows the longest cycle life (75.9 % capacity retention after 1000 cycles) in all sodium full cells, a usable capacity of 92 mAh g?1, and superior rate capability (65 mAh g?1 at a high rate of 2C). 相似文献
8.
A Sulfur Heterocyclic Quinone Cathode and a Multifunctional Binder for a High‐Performance Rechargeable Lithium‐Ion Battery 下载免费PDF全文
Dr. Ting Ma Dr. Qing Zhao Dr. Jianbin Wang Dr. Zeng Pan Prof. Jun Chen 《Angewandte Chemie (International ed. in English)》2016,55(22):6428-6432
We report a rational design of a sulfur heterocyclic quinone (dibenzo[b,i]thianthrene‐5,7,12,14‐tetraone=DTT) used as a cathode (uptake of four lithium ions to form Li4DTT) and a conductive polymer [poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate)=PEDOT:PSS) used as a binder for a high‐performance rechargeable lithium‐ion battery. Because of the reduced energy level of the lowest unoccupied molecular orbital (LUMO) caused by the introduced S atoms, the initial Li‐ion intercalation potential of DTT is 2.89 V, which is 0.3 V higher than that of its carbon analog. Meanwhile, there is a noncovalent interaction between DTT and PEDOT:PSS, which remarkably suppressed the dissolution and enhanced the conductivity of DTT, thus leading to the great improvement of the electrochemical performance. The DTT cathode with the PEDOT:PSS binder displays a long‐term cycling stability (292 mAh g?1 for the first cycle, 266 mAh g?1 after 200 cycles at 0.1 C) and a high rate capability (220 mAh g?1 at 1 C). This design strategy based on a noncovalent interaction is very effective for the application of small organic molecules as the cathode of rechargeable lithium‐ion batteries. 相似文献
9.
MoS2 Nanoflowers with Expanded Interlayers as High‐Performance Anodes for Sodium‐Ion Batteries 下载免费PDF全文
Zhe Hu Lixiu Wang Dr. Kai Zhang Dr. Jianbin Wang Prof. Fangyi Cheng Prof. Zhanliang Tao Prof. Jun Chen 《Angewandte Chemie (International ed. in English)》2014,53(47):12794-12798
MoS2 nanoflowers with expanded interlayer spacing of the (002) plane were synthesized and used as high‐performance anode in Na‐ion batteries. By controlling the cut‐off voltage to the range of 0.4–3 V, an intercalation mechanism rather than a conversion reaction is taking place. The MoS2 nanoflower electrode shows high discharge capacities of 350 mAh g?1 at 0.05 A g?1, 300 mAh g?1 at 1 A g?1, and 195 mAh g?1 at 10 A g?1. An initial capacity increase with cycling is caused by peeling off MoS2 layers, which produces more active sites for Na+ storage. The stripping of MoS2 layers occurring in charge/discharge cycling contributes to the enhanced kinetics and low energy barrier for the intercalation of Na+ ions. The electrochemical reaction is mainly controlled by the capacitive process, which facilitates the high‐rate capability. Therefore, MoS2 nanoflowers with expanded interlayers hold promise for rechargeable Na‐ion batteries. 相似文献
10.
Self‐Assembling Synthesis of Free‐standing Nanoporous Graphene–Transition‐Metal Oxide Flexible Electrodes for High‐Performance Lithium‐Ion Batteries and Supercapacitors 下载免费PDF全文
The synthesis of nanoporous graphene by a convenient carbon nanofiber assisted self‐assembly approach is reported. Porous structures with large pore volumes, high surface areas, and well‐controlled pore sizes were achieved by employing spherical silica as hard templates with different diameters. Through a general wet‐immersion method, transition‐metal oxide (Fe3O4, Co3O4, NiO) nanocrystals can be easily loaded into nanoporous graphene papers to form three‐dimensional flexible nanoarchitectures. When directly applied as electrodes in lithium‐ion batteries and supercapacitors, the materials exhibited superior electrochemical performances, including an ultra‐high specific capacity, an extended long cycle life, and a high rate capability. In particular, nanoporous Fe3O4–graphene composites can deliver a reversible specific capacity of 1427.5 mAh g?1 at a high current density of 1000 mA g?1 as anode materials in lithium‐ion batteries. Furthermore, nanoporous Co3O4–graphene composites achieved a high supercapacitance of 424.2 F g?1. This work demonstrated that the as‐developed freestanding nanoporous graphene papers could have significant potential for energy storage and conversion applications. 相似文献
11.
Fabrication of Fe‐Doped LiCoO2 Sandwich‐Like Nanocomposites as Excellent Performance Cathode Materials for Lithium‐Ion Batteries 下载免费PDF全文
Li Liu Dr. Huijuan Zhang Jiao Yang Yanping Mu Prof. Dr. Yu Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(52):19104-19111
In this article, the two‐layer sandwiched graphene@LiFe0.2Co0.8O2 nanoparticles (SG@LFCO) have been prepared and investigated as high‐rate and long‐life cathode materials for rechargeable lithium‐ion batteries. The materials possess a high‐surface area (267.1 m2 g?1) and lots of void spaces. By combining various favorable conditions, such as Fe doping, coating graphene, and designing novel morphology, the as‐prepared materials deliver a specific capacity of 115 mAh g?1 at 10 C. At the 0.1 C cycling rate, the capacity retention of 97.2 % is sustained after 250 cycles and a coulombic efficiency of around 97.6 % is obtained. 相似文献
12.
Structural and Electrochemical Study of Vanadium‐Doped TiO2 Ramsdellite with Superior Lithium Storage Properties for Lithium‐Ion Batteries 下载免费PDF全文
Dr. Juan Carlos Pérez‐Flores Dr. Markus Hoelzel Dr. Flaviano García‐Alvarado Dr. Alois Kuhn 《Chemphyschem》2016,17(7):1062-1069
Titanium‐oxide‐based materials are considered attractive and safe alternatives to carbonaceous anodes in Li‐ion batteries. In particular, the ramsdellite form TiO2(R) is known for its superior lithium‐storage ability as the bulk material when compared with other titanates. In this work, we prepared V‐doped lithium titanate ramsdellites with the formula Li0.5Ti1?xVxO2 (0≤x≤0.5) by a conventional solid‐state reaction. The lithium‐free Ti1?xVxO2 compounds, in which the ramsdellite framework remains virtually unaltered, are easily obtained by a simple aqueous oxidation/ion‐extraction process. Neutron powder diffraction is used to locate the Li channel site in Li0.5Ti1?xVxO2 compounds and to follow the lithium extraction by difference‐Fourier maps. Previously delithiated Ti1?xVxO2 ramsdellites are able to insert up to 0.8 Li+ per transition‐metal atom. The initial gravimetric capacities of 270 mAh g?1 with good cycle stability under constant current discharge conditions are among the highest reported for bulk TiO2‐related intercalation compounds for the threshold of one e? per formula unit. 相似文献
13.
Ting Jin Peng‐Fei Wang Qin‐Chao Wang Kunjie Zhu Tao Deng Jiaxun Zhang Wei Zhang Xiao‐Qing Yang Lifang Jiao Chunsheng Wang 《Angewandte Chemie (International ed. in English)》2020,59(34):14511-14516
P2‐type layered oxides suffer from an ordered Na+/vacancy arrangement and P2→O2/OP4 phase transitions, leading them to exhibit multiple voltage plateaus upon Na+ extraction/insertion. The deficient sodium in the P2‐type cathode easily induces the bad structural stability at deep desodiation states and limited reversible capacity during Na+ de/insertion. These drawbacks cause poor rate capability and fast capacity decay in most P2‐type layered oxides. To address these challenges, a novel high sodium content (0.85) and plateau‐free P2‐type cathode‐Na0.85Li0.12Ni0.22Mn0.66O2 (P2‐NLNMO) was developed. The complete solid‐solution reaction over a wide voltage range ensures both fast Na+ mobility (10?11 to 10?10 cm2 s?1) and small volume variation (1.7 %). The high sodium content P2‐NLNMO exhibits a higher reversible capacity of 123.4 mA h g?1, superior rate capability of 79.3 mA h g?1 at 20 C, and 85.4 % capacity retention after 500 cycles at 5 C. The sufficient Na and complete solid‐solution reaction are critical to realizing high‐performance P2‐type cathodes for sodium‐ion batteries. 相似文献
14.
Fluoroethylene Carbonate Enabling a Robust LiF‐rich Solid Electrolyte Interphase to Enhance the Stability of the MoS2 Anode for Lithium‐Ion Storage 下载免费PDF全文
Dr. Zhiqiang Zhu Dr. Yuxin Tang Zhisheng Lv Jiaqi Wei Dr. Yanyan Zhang Dr. Renheng Wang Dr. Wei Zhang Dr. Huarong Xia Mingzheng Ge Prof. Xiaodong Chen 《Angewandte Chemie (International ed. in English)》2018,57(14):3656-3660
As a high‐capacity anode for lithium‐ion batteries (LIBs), MoS2 suffers from short lifespan that is due in part to its unstable solid electrolyte interphase (SEI). The cycle life of MoS2 can be greatly extended by manipulating the SEI with a fluoroethylene carbonate (FEC) additive. The capacity of MoS2 in the electrolyte with 10 wt % FEC stabilizes at about 770 mAh g?1 for 200 cycles at 1 A g?1, which far surpasses the FEC‐free counterpart (ca. 40 mAh g?1 after 150 cycles). The presence of FEC enables a robust LiF‐rich SEI that can effectively inhibit the continual electrolyte decomposition. A full cell with a LiNi0.5Co0.3Mn0.2O2 cathode also gains improved performance in the FEC‐containing electrolyte. These findings reveal the importance of controlling SEI formation on MoS2 toward promoted lithium storage, opening a new avenue for developing metal sulfides as high‐capacity electrodes for LIBs. 相似文献
15.
Di Wang Fan Zhang Ping He Haoshen Zhou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(8):2377-2381
Li‐O2 batteries are promising candidates for next‐generation high‐energy‐density battery systems. However, the main problems of Li–O2 batteries include the poor rate capability of the cathode and the instability of the Li anode. Herein, an ester‐based liquid additive, 2,2,2‐trichloroethyl chloroformate, was introduced into the conventional electrolyte of a Li–O2 battery. Versatile effects of this additive on the oxygen cathode and the Li metal anode became evident. The Li–O2 battery showed an outstanding rate capability of 2005 mAh g?1 with a remarkably decreased charge potential at a large current density of 1000 mA g?1. The positive effect of the halide ester on the rate capacity is associated with the improved solubility of Li2O2 in the electrolyte and the increased diffusion rate of O2. Furthermore, the ester promotes the formation of a solid–electrolyte interphase layer on the surface of the Li metal, which restrains the loss and volume change of the Li electrode during stripping and plating, thereby achieving a cycling stability over 900 h and a Li capacity utilization of up to 10 mAh cm?2. 相似文献
16.
Ling Xie Yan Yan Huijuan Lin Kun Rui Aoming Huang Min Du Yu Shen Jixin Zhu 《化学:亚洲杂志》2020,15(7):1105-1109
Owing to the high specific capacity and energy density, metal oxides have become very promising electrodes for lithium‐ion batteries (LIBs). However, poor electrical conductivity accompanied with inferior cycling stability resulting from large volume changes are the main obstacles to achieve a high reversible capacity and stable cyclability. Herein, a facile and general approach to fabricate SnO2, Fe2O3 and Fe2O3/SnO2 fibers is proposed. The appealing structural features are favorable for offering a shortened lithium‐ion diffusion length, easy access for the electrolyte and reduced volume variation when used as anodes in LIBs. As a consequence, both single and hybrid oxides show satisfactory reversible capacities (1206 mAh g?1 for Fe2O3 and 1481 mAh g?1 for Fe2O3/SnO2 after 200 cycles at 200 mA g?1) and long lifespans. 相似文献
17.
Cobalt‐Doped FeS2 Nanospheres with Complete Solid Solubility as a High‐Performance Anode Material for Sodium‐Ion Batteries 下载免费PDF全文
Dr. Kai Zhang Mihui Park Limin Zhou Gi‐Hyeok Lee Jeongyim Shin Dr. Zhe Hu Dr. Shu‐Lei Chou Prof. Jun Chen Prof. Yong‐Mook Kang 《Angewandte Chemie (International ed. in English)》2016,55(41):12822-12826
Considering that the high capacity, long‐term cycle life, and high‐rate capability of anode materials for sodium‐ion batteries (SIBs) is a bottleneck currently, a series of Co‐doped FeS2 solid solutions with different Co contents were prepared by a facile solvothermal method, and for the first time their Na‐storage properties were investigated. The optimized Co0.5Fe0.5S2 (Fe0.5) has discharge capacities of 0.220 Ah g?1 after 5000 cycles at 2 A g?1 and 0.172 Ah g?1 even at 20 A g?1 with compatible ether‐based electrolyte in a voltage window of 0.8–2.9 V. The Fe0.5 sample transforms to layered NaxCo0.5Fe0.5S2 by initial activation, and the layered structure is maintained during following cycles. The redox reactions of NaxCo0.5Fe0.5S2 are dominated by pseudocapacitive behavior, leading to fast Na+ insertion/extraction and durable cycle life. A Na3V2(PO4)3/Fe0.5 full cell was assembled, delivering an initial capacity of 0.340 Ah g?1. 相似文献
18.
Heng‐guo Wang Haidong Wang Zhenjun Si Qiang Li Qiong Wu Qi Shao Lanlan Wu Yu Liu Yinghui Wang Shuyan Song Hongjie Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(30):10310-10314
Bipolar redox organics have attracted interest as electrode materials for energy storage owing to their flexibility, sustainability and environmental friendliness. However, an understanding of their application in all‐organic batteries, let alone dual‐ion batteries (DIBs), is in its infancy. Herein, we propose a strategy to screen a variety of phthalocyanine‐based bipolar organics. The self‐polymerizable bipolar Cu tetraaminephthalocyanine (CuTAPc) shows multifunctional applications in various energy storage systems, including lithium‐based DIBs using CuTAPc as the cathode material, graphite‐based DIBs using CuTAPc as the anode material and symmetric DIBs using CuTAPc as both the cathode and anode materials. Notably, in lithium‐based DIBs, the use of CuTAPc as the cathode material results in a high discharge capacity of 236 mAh g?1 at 50 mA g?1 and a high reversible capacity of 74.3 mAh g?1 after 4000 cycles at 4 A g?1. Most importantly, a high energy density of 239 Wh kg?1 and power density of 11.5 kW kg?1 can be obtained in all‐organic symmetric DIBs. 相似文献
19.
Fenghua Zheng Chenghao Yang Xunhui Xiong Jiawen Xiong Renzong Hu Yu Chen Meilin Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(44):13250-13254
Lithium‐rich layered oxides are promising cathode materials for lithium‐ion batteries and exhibit a high reversible capacity exceeding 250 mAh g−1. However, voltage fade is the major problem that needs to be overcome before they can find practical applications. Here, Li1.2Mn0.54Ni0.13Co0.13O2 (LLMO) oxides are subjected to nanoscale LiFePO4 (LFP) surface modification. The resulting materials combine the advantages of both bulk doping and surface coating as the LLMO crystal structure is stabilized through cationic doping, and the LLMO cathode materials are protected from corrosion induced by organic electrolytes. An LLMO cathode modified with 5 wt % LFP (LLMO–LFP5) demonstrated suppressed voltage fade and a discharge capacity of 282.8 mAh g−1 at 0.1 C with a capacity retention of 98.1 % after 120 cycles. Moreover, the nanoscale LFP layers incorporated into the LLMO surfaces can effectively maintain the lithium‐ion and charge transport channels, and the LLMO–LFP5 cathode demonstrated an excellent rate capacity. 相似文献
20.
Dr. Xiaofei Hu Jianchao Sun Zifan Li Qing Zhao Chengcheng Chen Prof. Jun Chen 《Angewandte Chemie (International ed. in English)》2016,55(22):6482-6486
Developing rechargeable Na–CO2 batteries is significant for energy conversion and utilization of CO2. However, the reported batteries in pure CO2 atmosphere are non‐rechargeable with limited discharge capacity of 200 mAh g?1. Herein, we realized the rechargeability of a Na–CO2 battery, with the proposed and demonstrated reversible reaction of 3 CO2+4 Na?2 Na2CO3+C. The battery consists of a Na anode, an ether‐based electrolyte, and a designed cathode with electrolyte‐treated multi‐wall carbon nanotubes, and shows reversible capacity of 60000 mAh g?1 at 1 A g?1 (≈1000 Wh kg?1) and runs for 200 cycles with controlled capacity of 2000 mAh g?1 at charge voltage <3.7 V. The porous structure, high electro‐conductivity, and good wettability of electrolyte to cathode lead to reduced electrochemical polarization of the battery and further result in high performance. Our work provides an alternative approach towards clean recycling and utilization of CO2. 相似文献