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1.
For the first time, environmentally friendly sulfur‐rich pyramidal MnS2 synthesized via a single‐step hydrothermal process is used as a high‐performance anode material in Li‐ion and Na‐ion batteries. The superior electrochemical performance of the MnS2 electrode along with its high compatibility with ether‐based electrolytes are analyzed in both half‐ and full‐cell configurations. The reversible capacities of ≈84 mAh g?1 and ≈74 mAh g?1 at a current density of 50 mA g?1 are retained in the Li‐ion and Na‐ion full‐cells, respectively, over 200 cycles with excellent capacity retentions. Moreover, important findings regarding activation processes in the presence of a new phase transition and protective electrolyte interphase layer are revealed using ab initio density function theory calculation and in situ potentio‐electrochemical impedance spectroscopy. The detailed complex redox mechanism of MnS2 in Li/Na half‐cells is also elucidated by ex situ X‐ray photoelectron spectroscopy.  相似文献   

2.
Hard carbon (HC) is the state‐of‐the‐art anode material for sodium‐ion batteries (SIBs). However, its performance has been plagued by the limited initial Coulombic efficiency (ICE) and mediocre rate performance. Here, experimental and theoretical studies are combined to demonstrate the application of lithium‐pretreated HC (LPHC) as high‐performance anode materials for SIBs by manipulating the solid electrolyte interphase in tetraglyme (TEGDME)‐based electrolyte. The LPHC in TEGDME can 1) deliver > 92% ICE and ≈220 mAh g?1 specific capacity, twice of the capacity (≈100 mAh g?1) in carbonate electrolyte; 2) achieve > 85% capacity retention over 1000 cycles at 1000 mA g?1 current density (4 C rate, 1 C = 250 mA g?1) with a specific capacity of ≈150 mAh g?1, ≈15 times of the capacity (10 mAh g?1) in carbonate. The full cell of Na3V2(PO4)3‐LPHC in TEGDME demonstrated close to theoretical specific capacity of ≈98 mAh g?1 based on Na3V2(PO4)3 cathode, ≈2.5 times of the value (≈40 mAh g?1) with nontreated HC. This work provides new perception on the anode development for SIBs.  相似文献   

3.
Identifying suitable electrode materials for sodium‐ion and potassium‐ion storage holds the key to the development of earth‐abundant energy‐storage technologies. This study reports an anode material based on self‐assembled hierarchical spheroid‐like KTi2(PO4)3@C nanocomposites synthesized via an electrospray method. Such an architecture synergistically combines the advantages of the conductive carbon network and allows sufficient space for the infiltration of the electrolyte from the porous structure, leading to an impressive electrochemical performance, as reflected by the high reversible capacity (283.7 mA h g?1 for Na‐ion batteries; 292.7 mA h g?1 for K‐ion batteries) and superior rate capability (136.1 mA h g?1 at 10 A g?1 for Na‐ion batteries; 133.1 mA h g?1 at 1 A g?1 for K‐ion batteries) of the resulting material. Moreover, the different ion diffusion behaviors in the two systems are revealed to account for the difference in rate performance. These findings suggest that KTi2(PO4)3@C is a promising candidate as an anode material for sodium‐ion and potassium‐ion batteries. In particular, the present synthetic approach could be extended to other functional electrode materials for energy‐storage materials.  相似文献   

4.
Inspired by the great success of graphite in lithium‐ion batteries, anode materials that undergo an intercalation mechanism are considered to provide stable and reversible electrochemical sodium‐ion storage for sodium‐ion battery (SIB) applications. Though MoS2 is a promising 2D material for SIBs, it suffers from deformation of its layered structure during repeated intercalation of Na+, resulting in undesirable electrochemical behaviors. In this study, vertically oriented MoS2 on nitrogenous reduced graphene oxide sheets (VO‐MoS2/N‐RGO) is presented with designed spatial geometries, including sheet density and height, which can deliver a remarkably high reversible capacity of 255 mA h g?1 at a current density of 0.2 A g?1 and 245 mA h g?1 at a current density of 1 A g?1, with a total fluctuation of 5.35% over 1300 cycles. These results are superior to those obtained with well‐developed hard carbon structures. Furthermore, a SIB full cell composed of the optimized VO‐MoS2/N‐RGO anode and a Na2V3(PO4)3 cathode reaches a specific capacity of 262 mA h g?1 (based on the anode mass) during 50 cycles, with an operated voltage range of 2.4 V, demonstrating the potentially rewarding SIB performance, which is useful for further battery development.  相似文献   

5.
The safety hazards and low Coulombic efficiency originating from the growth of lithium dendrites and decomposition of the electrolyte restrict the practical application of Li metal batteries (LMBs). Inspired by the low cost of low concentration electrolytes (LCEs) in industrial applications, dual‐salt LCEs employing 0.1 m Li difluorophosphate (LiDFP) and 0.4 m LiBOB/LiFSI/LiTFSI are proposed to construct a robust and conductive interphase on a Li metal anode. Compared with the conventional electrolyte using 1 m LiPF6, the ionic conductivity of LCEs is reduced but the conductivity decrement of the separator immersed in LCEs is moderate, especially for the LiDFP–LiFSI and LiDFP–LiTFSI electrolytes. The accurate Coulombic efficiency (CE) of the Li||Cu cells increases from 83.3% (electrolyte using 1 m LiPF6) to 97.6%, 94.5%, and 93.6% for LiDFP–LiBOB, LiDFP–LiFSI, and LiDFP–LiTFSI electrolytes, respectively. The capacity retention of Li||LiFePO4 cells using the LiDFP–LiBOB electrolyte reaches 95.4% along with a CE over 99.8% after 300 cycles at a current density of 2.0 mA cm?2 and the capacity reaches 103.7 mAh g?1 at a current density of up to 16.0 mA cm?2. This work provides a dual‐salt LCE for practical LMBs and presents a new perspective for the design of electrolytes for LMBs.  相似文献   

6.
Potassium ion hybrid capacitors have great potential for large‐scale energy devices, because of the high power density and low cost. However, their practical applications are hindered by their low energy density, as well as electrolyte decomposition and collector corrosion at high potential in potassium bis(fluoro‐sulfonyl)imide‐based electrolyte. Therefore, anode materials with high capacity, a suitable voltage platform, and stability become a key factor. Here, N‐doping carbon‐coated FeSe2 clusters are demonstrated as the anode material for a hybrid capacitor, delivering a reversible capacity of 295 mAh g?1 at 100 mA g?1 over 100 cycles and a high rate capability of 158 mAh g?1 at 2000 mA g?1 over 2000 cycles. Meanwhile, through density functional theory calculations, in situ X‐ray diffraction, and ex situ transmission electron microscopy, the evolution of FeSe2 to Fe3Se4 for the electrochemical reaction mechanism is successfully revealed. The battery‐supercapacitor hybrid using commercial activated carbon as the cathode and FeSe2/N‐C as the anode is obtained. It delivers a high energy density of 230 Wh kg?1 and a power density of 920 W kg?1 (the energy density and power density are calculated based on the total mass of active materials in the anode and cathode).  相似文献   

7.
The design and fabrication of high‐performance all‐plastic batteries is essentially important to achieve future flexible electronics. A major challenge in this field is the lack of stable and reliable soft organic electrodes with satisfactory performance. Here, a novel all‐plastic‐electrode based Li‐ion battery with a single flexible bi‐functional ladderized heterocyclic poly(quinone), (C6O2S2)n, as both cathode and anode is demonstrated. Benefiting from its unique ladder‐like quinone and dithioether structure, the as‐prepared polymer cathode shows a high energy density of 624 Wh kg?1 (vs lithium anode) and a stable battery life of 1000 cycles. Moreover, the as‐fabricated symmetric full‐battery delivers a large capacity of 249 mAh g?1 (at 20 mA g?1), a good capacity retention of 119 mAh g?1 after 250 cycles (at 1.0 A g?1) and a noteworthy energy density up to 276 Wh kg?1. The superior performance of poly(2,3‐dithiino‐1,4‐benzoquinone)‐based electrode rivals most of the state‐of‐the‐art demonstrations on organic‐based metal‐ion shuttling batteries. The study provides an effective strategy to develop stable bi‐functional electrode materials toward the next‐generation of high performance all‐plastic batteries.  相似文献   

8.
The symmetric batteries with an electrode material possessing dual cathodic and anodic properties are regarded as an ideal battery configuration because of their distinctive advantages over the asymmetric batteries in terms of fabrication process, cost, and safety concerns. However, the development of high‐performance symmetric batteries is highly challenging due to the limited availability of suitable symmetric electrode materials with such properties of highly reversible capacity. Herein, a triple‐hollow‐shell structured V2O5 (THS‐V2O5) symmetric electrode material with a reversible capacity of >400 mAh g?1 between 1.5 and 4.0 V and >600 mAh g?1 between 0.1 and 3.0 V, respectively, when used as the cathode and anode, is reported. The THS‐V2O5 electrodes assembled symmetric full lithium‐ion battery (LIB) exhibits a reversible capacity of ≈290 mAh g?1 between 2 and 4.0 V, the best performed symmetric energy storage systems reported to date. The unique triple‐shell structured electrode makes the symmetric LIB possessing very high initial coulombic efficiency (94.2%), outstanding cycling stability (with 94% capacity retained after 1000 cycles), and excellent rate performance (over 140 mAh g?1 at 1000 mA g?1). The demonstrated approach in this work leaps forward the symmetric LIB performance and paves a way to develop high‐performance symmetric battery electrode materials.  相似文献   

9.
All‐solid‐state batteries (ASSBs) with silicon anodes are promising candidates to overcome energy limitations of conventional lithium‐ion batteries. However, silicon undergoes severe volume changes during cycling leading to rapid degradation. In this study, a columnar silicon anode (col‐Si) fabricated by a scalable physical vapor deposition process (PVD) is integrated in all‐solid‐state batteries based on argyrodite‐type electrolyte (Li6PS5Cl, 3 mS cm?1) and Ni‐rich layered oxide cathodes (LiNi0.9Co0.05Mn0.05O2, NCM) with a high specific capacity (210 mAh g?1). The column structure exhibits a 1D breathing mechanism similar to lithium, which preserves the interface toward the electrolyte. Stable cycling is demonstrated for more than 100 cycles with a high coulombic efficiency (CE) of 99.7–99.9% in full cells with industrially relevant areal loadings of 3.5 mAh cm?2, which is the highest value reported so far for ASSB full cells with silicon anodes. Impedance spectroscopy revealed that anode resistance is drastically reduced after first lithiation, which allows high charging currents of 0.9 mA cm?2 at room temperature without the occurrence of dendrites and short circuits. Finally, in‐operando monitoring of pouch cells gave valuable insights into the breathing behavior of the solid‐state cell.  相似文献   

10.
A novel combination of hard carbon anode sodium pre‐loading and a tailored electrolyte is used to prepare room temperature sodium‐sulfur full cell batteries. The electrochemical loading with sodium ions is realized in a specific mixture of diethyl carbonate, ethylene carbonate, and fluoroethylene carbonate electrolyte in order to create a first solid electrolyte interface (SEI) on the anode surface. Combining such anodes with a porous carbon/sulfur composite cathode results in full cells with a significantly decreased polysulfide shuttle when compared to half cells combined with metallic sodium anodes. Further optimization involves the use of Na2S/P2S5 doped tetraethylene glycol dimethyl ether based electrolyte in the full cell for the formation of a second SEI, reducing polysulfide shuttle even further. More importantly, the electrochemical discharge processes in the cell are improved by adding this dissolved complexation agent to the electrolyte. As a result of this combination sodium‐sulfur cells with tailored cathode materials and electrolytes can achieve high discharge capacities up to 980 mAh g?1sulfur and 1000 cycles with 200 mAh g?1sulfur remaining capacity, at room temperature.  相似文献   

11.
The application of lithium (Li) metal anodes in Li metal batteries has been hindered by growth of Li dendrites, which lead to short cycling life. Here a Li‐ion‐affinity leaky film as a protection layer is reported to promote a dendrite‐free Li metal anode. The leaky film induces electrokinetic phenomena to enhance Li‐ion transport, leading to a reduced Li‐ion concentration polarization and homogeneous Li‐ion distribution. As a result, the dendrite‐free Li metal anode during Li plating/stripping is demonstrated even at an extremely high deposition capacity (6 mAh cm?2) and current density (40 mA cm?2) with improved Coulombic efficiencies. A full cell battery with the leaky‐film protected Li metal as the anode and high‐areal‐capacity LiNi0.8Co0.1Mn0.1O2 (NCM‐811) (≈4.2 mAh cm?2) or LiFePO4 (≈3.8 mAh cm?2) as the cathode shows improved cycling stability and capacity retention, even at lean electrolyte conditions.  相似文献   

12.
All‐solid‐state sodium metal batteries (SSMBs) are of great interest for their high theoretical capacity, nonflammability, and relatively low cost owing partially to the abundance of sodium recourses. However, it is challenging to fabricate SSMBs because compared with their counterparts, which contain lithium metal, sodium metal is mechanically softer and more reactive toward the electrolyte. Herein, the synthesis and electrochemical properties of newly designed sodium‐containing hybrid network solid polymer electrolytes (SPEs) and their application in SSMBs are reported. The hybrid network is synthesized by controlled crosslinking of octakis(3‐glycidyloxypropyldimethylsiloxy)octasilsesquioxane and amine‐terminated polyethylene glycol in existence with sodium perchlorate (NaClO4). Plating and stripping experiments using symmetric cells show prolonged cycle life of the SPEs, >5150 and 3550 h at current density of 0.1 and 0.5 mA cm?2, respectively. The results for the first time show that the SPE|sodium metal interface migrates into the SPE phase upon cycling. SSMBs fabricated with the hybrid SPE sandwiched between sodium metal anode and bilayered δ‐NaxV2O5 cathode exhibit record‐high specific capacity for solid sodium‐ion batteries of 305 mAh g?1 and excellent Coulombic efficiency. This work demonstrates that the hybrid network SPEs are promising for SSMB applications.  相似文献   

13.
Metal phosphides are promising anode candidates for sodium‐ion batteries (SIBs) due to their high specific capacity and low operating potential but suffer from poor cycling stability caused by huge volume expansion and poor solid‐state ion transfer rate. Herein, a new strategy to grow a new class of mesoporous metal phosphide nanoarrays on carbon felt (CF) as binder‐free anodes for SIBs is reported. The resultant integrated electrodes demonstrate excellent cycling life up to 1000 times (>90% retention rate) and high rate capability of 535 mAh g?1 at a current density of 4 A g?1. Detailed characterization reveals that the synergistic effect of unique mesoporous structure for accommodating huge volume expansion during sodiation/desodiation process, ultrasmall primary particle size (≈10 nm) for providing larger electrode/electrolyte contact area and shorter ion diffusion distance, and 3D conductive networks for facilitating the electrochemical reaction, leads to the extraordinary battery performance. Remarkably, a full SIB using the new CoP4/CF anode and a Na3V2(PO4)2F3 cathode delivers an average operating voltage of ≈3.0 V, a reversible capacity of 553 mAh g?1, and very high energy density of ≈280 Wh kg?1 for SIBs. A flexible SIB with outstanding mechanical strength based on this binder‐free new anode is also demonstrated.  相似文献   

14.
A challenge still remains to develop high‐performance and cost‐effective air electrode for Li‐O2 batteries with high capacity, enhanced rate capability and long cycle life (100 times or above) despite recent advances in this field. In this work, a new design of binder‐free air electrode composed of three‐dimensional (3D) graphene (G) and flower‐like δ‐MnO2 (3D‐G‐MnO2) has been proposed. In this design, graphene and δ‐MnO2 grow directly on the skeleton of Ni foam that inherits the interconnected 3D scaffold of Ni foam. Li‐O2 batteries with 3D‐G‐MnO2 electrode can yield a high discharge capacity of 3660 mAh g?1 at 0.083 mA cm?2. The battery can sustain 132 cycles at a capacity of 492 mAh g?1 (1000 mAh gcarbon ?1) with low overpotentials under a high current density of 0.333 mA cm?2. A high average energy density of 1350 Wh Kg?1 is maintained over 110 cycles at this high current density. The excellent catalytic activity of 3D‐G‐MnO2 makes it an attractive air electrode for high‐performance Li‐O2 batteries.  相似文献   

15.
A high‐rate of oxygen redox assisted by cobalt in layered sodium‐based compounds is achieved. The rationally designed Na0.6[Mg0.2Mn0.6Co0.2]O2 exhibits outstanding electrode performance, delivering a discharge capacity of 214 mAh g?1 (26 mA g?1) with capacity retention of 87% after 100 cycles. High rate performance is also achieved at 7C (1.82 A g?1) with a capacity of 107 mAh g?1. Surprisingly, the Na0.6[Mg0.2Mn0.6Co0.2]O2 compound is able to deliver capacity for 1000 cycles at 5C (at 1.3 A g?1), retaining 72% of its initial capacity of 108 mAh g?1. X‐ray absorption spectroscopy analysis of the O K‐edge indicates the oxygen‐redox species (O2?/1?) is active during cycling. First‐principles calculations show that the addition of Co reduces the bandgap energy from ≈2.65 to ≈0.61 eV and that overlapping of the Co 3d and O 2p orbitals facilitates facile electron transfer, enabling the long‐term reversibility of the oxygen redox, even at high rates. To the best of the authors' knowledge, this is the first report on high‐rate oxygen redox in sodium‐based cathode materials, and it is believed that the findings will open a new pathway for the use of oxygen‐redox‐based materials for sodium‐ion batteries.  相似文献   

16.
Thin solid‐state electrolytes with nonflammability, high ionic conductivity, low interfacial resistance, and good processability are urgently required for next‐generation safe, high energy density lithium metal batteries. Here, a 3D Li6.75La3Zr1.75Ta0.25O12 (LLZTO) self‐supporting framework interconnected by polytetrafluoroethylene (PTFE) binder is prepared through a simple grinding method without any solvent. Subsequently, a garnet‐based composite electrolyte is achieved through filling the flexible 3D LLZTO framework with a succinonitrile solid electrolyte. Due to the high content of garnet ceramic (80.4 wt%) and high heat‐resistance of the PTFE binder, such a composite electrolyte film with nonflammability and high processability exhibits a wide electrochemical window of 4.8 V versus Li/Li+ and high ionic transference number of 0.53. The continuous Li+ transfer channels between interconnected LLZTO particles and succinonitrile, and the soft electrolyte/electrode interface jointly contribute to a high ambient‐temperature ionic conductivity of 1.2 × 10?4 S cm?1 and excellent long‐term stability of the Li symmetric battery (stable at a current density of 0.1 mA cm?2 for over 500 h). Furthermore, as‐prepared LiFePO4|Li and LiNi0.5Mn0.3Co0.2O2|Li batteries based on the thin composite electrolyte exhibit high discharge specific capacities of 153 and 158 mAh g?1 respectively, and desirable cyclic stabilities at room temperature.  相似文献   

17.
Alloy materials such as Si and Ge are attractive as high‐capacity anodes for rechargeable batteries, but such anodes undergo severe capacity degradation during discharge–charge processes. Compared to the over‐emphasized efforts on the electrode structure design to mitigate the volume changes, understanding and engineering of the solid‐electrolyte interphase (SEI) are significantly lacking. This work demonstrates that modifying the surface of alloy‐based anode materials by building an ultraconformal layer of Sb can significantly enhance their structural and interfacial stability during cycling. Combined experimental and theoretical studies consistently reveal that the ultraconformal Sb layer is dynamically converted to Li3Sb during cycling, which can selectively adsorb and catalytically decompose electrolyte additives to form a robust, thin, and dense LiF‐dominated SEI, and simultaneously restrain the decomposition of electrolyte solvents. Hence, the Sb‐coated porous Ge electrode delivers much higher initial Coulombic efficiency of 85% and higher reversible capacity of 1046 mAh g?1 after 200 cycles at 500 mA g?1, compared to only 72% and 170 mAh g?1 for bare porous Ge. The present finding has indicated that tailoring surface structures of electrode materials is an appealing approach to construct a robust SEI and achieve long‐term cycling stability for alloy‐based anode materials.  相似文献   

18.
Potassium‐based dual‐ion batteries (KDIBs) have emerged as a new generation of rechargeable batteries, due to their high cell voltage, low cost, and the natural abundance of potassium resources. However, the low capacity and poor cycling stability largely hinder the further development of KDIBs. Herein, the fabrication of hierarchically porous N‐doped carbon fibers (HPNCFs) as a free‐standing anode for high‐performance KDIBs is reported. With a free‐standing hierarchical structure (micro/meso/macropores and nanochannels) and high‐content of nitrogen doping, the HPNCFs not only provide intrinsic electron pathways and efficient ion transport channels, but also afford sufficient free space to tolerate the volume change during cycling. Consequently, the KDIBs made from a graphite cathode and an optimized HPNCFs anode deliver a high reversible capacity of 197 mAh g?1 at a specific current of 50 mA g?1, and excellent cycling stability (65 mAh g?1 after 346 cycles at a specific current of 100 mA g?1, the capacity calculation of the KDIBs is based on the mass of the anode). These results indicate that the properly designed HPNCFs can effectively improve the capacity and cycling stability of the KDIBs, indicating a great potential for applications in the field of high‐performance energy‐storage devices.  相似文献   

19.
Different from previously reported mechanical alloying route to synthesize Sn x P3, novel Sn4P3/reduced graphene oxide (RGO) hybrids are synthesized for the first time through an in situ low‐temperature solution‐based phosphorization reaction route from Sn/RGO. Sn4P3 nanoparticles combining with advantages of high conductivity of Sn and high capacity of P are homogenously loaded on the RGO nanosheets, interconnecting to form 3D mesoporous architecture nanostructures. The Sn4P3/RGO hybrid architecture materials exhibit significantly improved electrochemical performance of high reversible capacity, high‐rate capability, and excellent cycling performance as sodium ion batteries (SIBs) anode materials, showing an excellent reversible capacity of 656 mA h g?1 at a current density of 100 mA g?1 over 100 cycles, demonstrating a greatly enhanced rate capability of a reversible capacity of 391 mA h g?1 even at a high current density of 2.0 A g?1. Moreover, Sn4P3/RGO SIBs anodes exhibit a superior long cycling life, delivering a high capacity of 362 mA h g?1 after 1500 cycles at a high current density of 1.0 A g?1. The outstanding cycling performance and rate capability of these porous hierarchical Sn4P3/RGO hybrid anodes can be attributed to the advantage of porous structure, and the synergistic effect between Sn4P3 nanoparticles and RGO nanosheets.  相似文献   

20.
Aqueous zinc ion batteries (AZIBs) are steadily gaining attention based on their attractive merits regarding cost and safety. However, there are many obstacles to overcome, especially in terms of finding suitable cathode materials and elucidating their reaction mechanisms. Here, a mixed‐valence vanadium oxide, V6O13, that functions as a stable cathode material in mildly acidic aqueous electrolytes is reported. Paired with a zinc metal anode, this material exhibits performance metrics of 360 mAh g?1 at 0.2 A g?1, 92% capacity retention after 2000 cycles, and 145 mAh g?1 at a current density of 24.0 A g?1. A combination of experiments and density functional theory calculations suggests that hydrated intercalation, where water molecules are cointercalated with Zn ions upon discharge, accounts for the aforementioned electrochemical performance. This intercalation mechanism facilitates Zn ion diffusion throughout the host lattice and electrode–electrolyte interface via electrostatic shielding and concurrent structural stabilization. Through a correlation of experimental data and theoretical calculations, the promise of utilizing hydrated intercalation as a means to achieve high‐performance AZIBs is demonstrated.  相似文献   

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