摘要 :
The electrochemistries between alkali metals (Li, Na, K, etc.) and chalcogen elements (O, S, Se, Te, etc.) are becoming increasingly important in the field of electrochemical energy storage, because they can be used in advanced el...
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The electrochemistries between alkali metals (Li, Na, K, etc.) and chalcogen elements (O, S, Se, Te, etc.) are becoming increasingly important in the field of electrochemical energy storage, because they can be used in advanced electrochemical energy storage batteries with higher energy densities for powering our future society. Among the best candidates for next-generation high-energy-storage systems, rechargeable metal batteries based on the chalocogen elements such as O and S hold high theoretical energy densities, making them especially attractive.
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摘要 :
The electrochemistries between alkali metals (Li, Na, K, etc.) and chalcogen elements (O, S, Se, Te, etc.) are becoming increasingly important in the field of electrochemical energy storage, because they can be used in advanced el...
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The electrochemistries between alkali metals (Li, Na, K, etc.) and chalcogen elements (O, S, Se, Te, etc.) are becoming increasingly important in the field of electrochemical energy storage, because they can be used in advanced electrochemical energy storage batteries with higher energy densities for powering our future society. Among the best candidates for next-generation high-energy-storage systems, rechargeable metal batteries based on the chalocogen elements such as O and S hold high theoretical energy densities, making them especially attractive.
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摘要 :
Rechargeable batteries are key components in the energy-conversion-storage-usage chains to implement their stable and efficient utilization. Amongst all of the commercially available secondary batteries, lithium-ion batteries repr...
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Rechargeable batteries are key components in the energy-conversion-storage-usage chains to implement their stable and efficient utilization. Amongst all of the commercially available secondary batteries, lithium-ion batteries represent the state-of-the-art technology. Recently, with the increasing demand for efficient and economic energy storage, advanced post Li-ion batteries, including Li-O_2 and Li-S systems, as well as other metal-ion systems such as Na-ion and Mg-ion systems, have become more and more attractive candidates for the next-generation high-energy batteries. Electrode materials (especially, nanostructured electrode materials) could play an important role in improving the performance of the post Li-ion batteries. Here, we report our recent progress in this field covering Li-S batteries, Li-Se batteries, Na-ion batteries, room-temperature Na-S batteries, as well as Mg-ion batteries.
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摘要 :
Rechargeable batteries are key components in the energy-conversion-storage-usage chains to implement their stable and efficient utilization. Amongst all of the commercially available secondary batteries, lithium-ion batteries repr...
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Rechargeable batteries are key components in the energy-conversion-storage-usage chains to implement their stable and efficient utilization. Amongst all of the commercially available secondary batteries, lithium-ion batteries represent the state-of-the-art technology. Recently, with the increasing demand for efficient and economic energy storage, advanced post Li-ion batteries, including Li-O_2 and Li-S systems, as well as other metal-ion systems such as Na-ion and Mg-ion systems, have become more and more attractive candidates for the next-generation high-energy batteries. Electrode materials (especially, nanostructured electrode materials) could play an important role in improving the performance of the post Li-ion batteries. Here, we report our recent progress in this field covering Li-S batteries, Li-Se batteries, Na-ion batteries, room-temperature Na-S batteries, as well as Mg-ion batteries.
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A potential Lithium-ion battery anode material Li4-xNaxTi5O12 (0≤x≤0.15) has been synthesized via a facile hydrothermal method with short processing time and low temperature. The XRD and FE-SEM results indicate that samples with...
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A potential Lithium-ion battery anode material Li4-xNaxTi5O12 (0≤x≤0.15) has been synthesized via a facile hydrothermal method with short processing time and low temperature. The XRD and FE-SEM results indicate that samples with Na-doped are well-crystallized and have more homogeneous particle distributions with smaller overall particle size in the range of 300-600nm. Electrochemical tests reveal that Na-doped samples exhibit impressive specific capacity and cycle stability compared to pristine Li_4Ti_5O_(12) at high rate. The Li_(3.9)Na_(0.1)Ti_5O_(12) electrode deliver an initial specific discharge capacity of 169mAh/g at 0.5C and maintained at 150.4mAh/g even after 40 cycles with the reversible retention of 88.99%. Finally, a simple solvothermal reduction method was used to fabricate Li3.9Na0.1Ti5O12/graphene (Li3.9Na0.1Ti5O12/G) composite. Galvanostatic charge-discharge tests demonstrate that this sample has remarkable capacities of 197.4mAh/g and 175.5mAh/g at 0.2C and 0.5C rate, respectively. This indicates that the Li3.9Na0.1Ti5O12/G composite is a promising anode material for using in lithium-ion batteries.
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Cobalt-free Li-rich Mn-based cathode materials are considered to be the next generation of Li-ion batteries due to high discharge capacities and high safety feature. However, there are still several serious issues that need to be ...
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Cobalt-free Li-rich Mn-based cathode materials are considered to be the next generation of Li-ion batteries due to high discharge capacities and high safety feature. However, there are still several serious issues that need to be solved urgently, such as low rate capability, poor cycling performance and voltage fading. Na doping or substitution is introduced to improve the electrochemical properties of Li_(1.2)Mn_(0.6)Ni_(0.2)O_2, which is synthesized by sol-gel method. The effect of Na doping or substitution on the morphological, structural and electrochemical properties was systematically studied and analyzed by scanning electron microscope (SEM), X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cell test system and electrochemical workstation. These results illustrate that lattice layer spacing is enlarged by Na doping or substitution, which is beneficial for the diffusion of Li-ion, and the voltage fading is successfully suppressed. The best electrochemical properties were obtained when Na doping, which is attributed to the stronger structural stability and better reversibility of Li~+ during the initial charge and discharge process.
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High-performance and cost-effective rechargeable batteries are key to the success of electric vehicles and large-scale energy storage systems. Extensive research has focused on the development of new high-energy electrodes that ca...
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High-performance and cost-effective rechargeable batteries are key to the success of electric vehicles and large-scale energy storage systems. Extensive research has focused on the development of new high-energy electrodes that can store more lithium. However, the current status of lithium batteries based on redox reactions of heavy transition metals still remains far below the demands required for the proposed applications. In this presentation, we introduce novel approaches toward transition metal-free cathode materials. In the first part, it is demonstrated by using tunable functional groups on graphene nano-platelets as redox centers. The electrode can deliver high capacity of 250 mAh g"1, power of 20 kW kg"1 in an acceptable cathode voltage range, and provide excellent cyclability up to thousands of repeated charge/discharge cycles. The simple, mass-scalable synthetic route for the functionalized graphene nano-platelets is also proposed.
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The relationship between the volume available within the crystal structure of a material and the size of charge-carrying ions is investigated by evaluating the performance of two manganese oxides with controlled variations in crys...
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The relationship between the volume available within the crystal structure of a material and the size of charge-carrying ions is investigated by evaluating the performance of two manganese oxides with controlled variations in crystal tunnels, α-MnO_2 (K_(0.11)MnO_2) and todorokite MnO_2 (Mg_(0.20)MnO_2), in Li-ion and Na-ion batteries. These materials consist of MnO_6 octahedra building blocks arranged into square tunnel configurations around different stabilizing cations, with α-MnO_2 possessing structural tunnels of 4.6 A by 4.6 A and todorokite MnO_2 possessing tunnels of 6.9 A by 6.9 A. Electrochemical testing of these materials revealed that despite its smaller crystal tunnel size, α-MnO_2 exhibits higher capacities in both battery systems. However, at higher current rates it was found that todorokite MnO_2 maintained a greater amount of its initial capacity. These findings provide valuable insight into the relationship between crystal structure composition and charge-carrying ion size to develop more efficient intercalation cathodes for Li-ion and Na-ion batteries.
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