Flexible electrochemical energy storage devices have attracted extensive attention as promising power sources for the ever-growing field of flexible and wearable electronic products. However, the ...rational design of a novel electrode structure with a good flexibility, high capacity, fast charge-discharge rate and long cycling lifetimes remains a long-standing challenge for developing next-generation flexible energy-storage materials. Herein, we develop a facile and general approach to three-dimensional (3D) interconnected porous nitrogen-doped graphene foam with encapsulated Ge quantum dot/nitrogen-doped graphene yolk-shell nano architecture for high specific reversible capacity (1,220 mAh g
), long cycling capability (over 96% reversible capacity retention from the second to 1,000 cycles) and ultra-high rate performance (over 800 mAh g
at 40 C). This work paves a way to develop the 3D interconnected graphene-based high-capacity electrode material systems, particularly those that suffer from huge volume expansion, for the future development of high-performance flexible energy storage systems.
Limited by the size of microelectronics, as well as the space of electrical vehicles, there are tremendous demands for lithium-ion batteries with high volumetric energy densities. Current lithium-ion ...batteries, however, adopt graphite-based anodes with low tap density and gravimetric capacity, resulting in poor volumetric performance metric. Here, by encapsulating nanoparticles of metallic tin in mechanically robust graphene tubes, we show tin anodes with high volumetric and gravimetric capacities, high rate performance, and long cycling life. Pairing with a commercial cathode material LiNi
Mn
Co
O
, full cells exhibit a gravimetric and volumetric energy density of 590 W h Kg
and 1,252 W h L
, respectively, the latter of which doubles that of the cell based on graphite anodes. This work provides an effective route towards lithium-ion batteries with high energy density for a broad range of applications.
The application of graphene for electrochemical energy storage has received tremendous attention; however, challenges remain in synthesis and other aspects. Here we report the synthesis of ...high-quality, nitrogen-doped, mesoporous graphene particles through chemical vapor deposition with magnesium-oxide particles as the catalyst and template. Such particles possess excellent structural and electrochemical stability, electronic and ionic conductivity, enabling their use as high-performance anodes with high reversible capacity, outstanding rate performance (e.g., 1,138 mA h g
at 0.2 C or 440 mA h g
at 60 C with a mass loading of 1 mg cm
), and excellent cycling stability (e.g., >99% capacity retention for 500 cycles at 2 C with a mass loading of 1 mg cm
). Interestingly, thick electrodes could be fabricated with high areal capacity and current density (e.g., 6.1 mA h cm
at 0.9 mA cm
), providing an intriguing class of materials for lithium-ion batteries with high energy and power performance.
Abstract
The sluggish electrochemical kinetics of sulfur species has impeded the wide adoption of lithium-sulfur battery, which is one of the most promising candidates for next-generation energy ...storage system. Here, we present the electronic and geometric structures of all possible sulfur species and construct an electronic energy diagram to unveil their reaction pathways in batteries, as well as the molecular origin of their sluggish kinetics. By decoupling the contradictory requirements of accelerating charging and discharging processes, we select two pseudocapacitive oxides as electron-ion source and drain to enable the efficient transport of electron/Li
+
to and from sulfur intermediates respectively. After incorporating dual oxides, the electrochemical kinetics of sulfur cathode is significantly accelerated. This strategy, which couples a fast-electrochemical reaction with a spontaneous chemical reaction to bypass a slow-electrochemical reaction pathway, offers a solution to accelerate an electrochemical reaction, providing new perspectives for the development of high-energy battery systems.
Despite the progress made on the production of graphene using liquid‐phase exfoliation methods, the fabrication of graphene with both high conductivity and dispersibility remains challenging. Through ...catalytic exfoliation of graphite, an effective synthesis method for graphene with large lateral size (≈10 µm), high conductivity (926 S cm–1), and excellent water solubility (≈10 mg mL–1) is reported herein. Such graphene can be used broadly for applications such as lithium ion batteries, where both high conductivity and dispersibility are required. As an example, the synthesis of graphene and lithium‐iron‐phosphate composites is demonstrated, which leads to electrodes with dramatically improved cycling stability and rate performance. Adaption of such material leads to electrodes with volumetric energy density as high as 658.7 and 287.6 W h L–1 under 0.5 and 20 C, respectively, which is significantly higher than that of commercial LiFePO4 (394.7 and 13.5 W h L–1 at 0.5 and 20 C, respectively). This work provides a new method of making high‐conductivity–dispersibility graphene for various applications.
This work reports an effective synthesis of graphene with a large lateral size, high conductivity, and excellent water solubility through catalytic exfoliation of graphite. To examine its use in lithium ion batteries, such a graphene is further assembled with LiFePO4 through spray drying to form a composite cathode, which leads to a dramatically improved cycling stability and rate performance.
The overuse of fossil fuels has created a dual challenge for humanity, namely energy and environmental concerns. Excessive carbon emissions have resulted in a range of global climate issues. It’s of ...great practical significance to capture the excessive carbon dioxide emissions and convert them into high value-added chemicals or fuels. Methane is an important carrier for chemical bond energy storage due to its high mass calorific value. Carbon dioxide methanation is a promising process for reducing carbon dioxide emissions. This review introduces recent research progress on carbon dioxide methanation using thermal catalytic, bioconversion, photocatalytic, and electrocatalytic technologies. A dual-function integrated design integrating carbon dioxide capture and methanation is proposed, which not only realizes on-site capture and utilization, but also improves the manufacturability and economic benefits of the entire process.
•The reaction mechanisms such as the CO pathway, the Formate pathway, and the RWGS+CO-Hydro pathway were clarified.•The latest advances in catalyst development of carbon dioxide methanation were introduced.•A dual-function integrated design integrating carbon dioxide capture and methanation was proposed.
The key properties of yolk-shell architecture in improving electrochemical performance lies in its uniformity and the appropriate void space, which can expand/contract freely upon lithium alloying ...and leaching without damaging the outer shell, while being achievable with minimal sacrifice of volumetric energy density. Therefore, we developed a highly controllable strategy to fabricate a uniform porous germanium@polypyrrole (PGe@PPy) yolk-shell architecture with conformal Al
O
sacrificial layer by atomic layer deposition (ALD) process. The PGe@PPy yolk-shell anode fabricated with 300 ALD cycles delivers excellent electrochemical performance: high reversible capacity (1,220 mA hr g
), long cycle performance (>95% capacity retention after 1,000 cycles), and excellent rate capability (>750 mA hr g
at 32 A g
). Electrodes with high areal capacity and current density were also successfully fabricated, opening a new pathway to develop high-capacity electrode materials with large volume expansion.
In this work, an economical route based on hydrothermal and layer-by-layer (LBL) self-assembly processes has been developed to synthesize unique Al2O3-modified LiV3O8 nanosheets, comprising a core of ...LiV3O8 nanosheets and a thin Al2O3 nanolayer. The thickness of the Al2O3 nanolayer can be tuned by altering the LBL cycles. When evaluated for their lithium-storage properties, the 1 LBL Al2O3-modified LiV3O8 nanosheets exhibit a high discharge capacity of 191 mA h g−1 at 300 mA g−1 (1C) over 200 cycles and excellent rate capability, demonstrating that enhanced physical and/or chemical properties can be achieved through proper surface modification.
•The Al2O3-modified LiV3O8 nanosheets was prepared through self-assembly process.•The thickness of the Al2O3 layer can be tuned by altering the layer-by-layer cycles.•The cyclic stability and high rate capability are improved due to Al2O3 modifying.
•The influence of the microstructure of carbon materials for CO2 conversion on energy storage performance was analyzed.•The basic design principles of carbon-based energy storage materials were ...summarized.•The key issues such as rapid capture of CO2, high-efficiency conversion, and controllable product form were clarified.•The latest advances in the preparation of high value-added carbon materials from carbon dioxide were introduced.
Since the industrial revolution, the consumption of fossil fuels has increased year by year, which has resulted in increasing greenhouse gas emissions. Carbon capture, utilization and storage technology has received extensive attention as a technology for converting atmospheric carbon dioxide into high value-added materials. Carbon materials, as ideal materials for various energy storage devices, have attracted extensive research. Therefore, the selective reduction of CO2 to carbon materials with high added value is a promising solution, which can not only effectively alleviate the greenhouse effect, but also promote the development of the energy storage field. This review introduces the research work of high-value conversion of carbon dioxide into carbon materials and its impact on the performance of energy storage devices in recent years. In particular, we emphasize the reaction processes during CO2 conversion, which can build an understanding of the science and technology involved in the control of interfacial properties, microstructure, and pore structure of CO2-converted carbon nanomaterials. We also summarized the basic design principles for the application of carbon nanomaterials in the field of energy storage. The effect of the microstructure and interface properties of carbon materials converted from CO2 on the energy storage performance are further analyzed. Finally, prospects and discussions are made on the challenges of future development.
With the rapid development of society, the growing interest in flexible electronics has led to remarkable progress in recent advances in the manufacture of flexible electronics ...
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