Xiyue Zhang

Achieving Ultrahigh Energy Density and Long Durability in a Flexible Rechargeable Quasi‐Solid‐State Zn–MnO2 Battery

Advanced flexible batteries with high energy density and long cycle life are an important research target. Herein, the first paradigm of a high-performance and stable flexible rechargeable quasi-solid-state Zn-MnO2 battery is constructed by engineering MnO2 electrodes and gel electrolyte. Benefiting from a poly(3,4-ethylenedioxythiophene) (PEDOT) buffer layer and a Mn2+ -based neutral electrolyte, the fabricated Zn-MnO2 @PEDOT battery presents a remarkable capacity of 366.6 mA h g-1 and good cycling performance (83.7% after 300 cycles) in aqueous electrolyte. More importantly, when using PVA/ZnCl2 /MnSO4 gel as electrolyte, the as-fabricated quasi-solid-state Zn-MnO2 @PEDOT battery remains highly rechargeable, maintaining more than 77.7% of its initial capacity and nearly 100% Coulombic efficiency after 300 cycles. Moreover, this flexible quasi-solid-state Zn-MnO2 battery achieves an admirable energy density of 504.9 W h kg-1 (33.95 mW h cm-3 ), together with a peak power density of 8.6 kW kg-1 , substantially higher than most recently reported flexible energy-storage devices. With the merits of impressive energy density and durability, this highly flexible rechargeable Zn-MnO2 battery opens new opportunities for powering portable and wearable electronics.

Facile electrochemical synthesis of CeO2 hierarchical nanorods and nanowires with excellent photocatalytic activities

In this work, we developed a simple, cost-effective and controllable electrochemical method to synthesize free-standing CeO2 hierarchical nanorods and nanowires. Due to their hierarchical one-dimensional nanostructures and increased surface areas, both the CeO2 hierarchical nanorods and nanowires exhibit substantially higher photocatalytic performance than the commercial CeO2 nanoparticles in the degradation of methyl orange.

Recent advances and challenges of stretchable supercapacitors based on carbon materials

Stretchable energy storage devices are essential for the development of stretchable electronics that can maintain their electronic performance while sustain large mechanical strain. In this context, stretchable supercapacitors (SSCs) are regarded as one of the most promising power supply in stretchable electronic devices due to their high power densities, fast charge-discharge capability, and modest energy densities. Carbon materials, including carbon nanotubes, graphene, and mesoporous carbon, hold promise as electrode materials for SSCs for their large surface area, excellent electrical, mechanical, and electrochemical properties. Much effort has been devoted to developing stretchable, carbon-based SSCs with different structure/performance characteristics, including conventional planar/textile, wearable fiber-shaped, transparent, and solid-state devices with aesthetic appeal. This review summarizes recent advances towards the development of carbon-based SSCs. Challenges and important directions in this emerging field are also discussed.摘要可伸缩型储能器件的研究对现代电子产品的发展至关重要. 可伸缩型超级电容器(SSCs)能在大的应力应变条件下保持其储能性能不 受损害, 是近年来发展的一种新型、高效、实用的储能装置. 碳纳米管和石墨烯等碳材料由于具有较大的比表面积、优良的导电性和机 械性能优势, 以及突出的电化学性能, 成为伸缩型超级电容器电极材料的新选择. 近年来, 为进一步提高碳基可伸缩型超级电容器的性能, 许多课题组致力于其一维线状、二维平面/网状和三维立体结构的探索研究中. 本篇综述总结了近年来碳基可伸缩型超级电容器的研究策 略和方法, 并通过分析讨论该新兴领域的一些重要挑战, 提出未来可行的研究方向.

An Ultrastable and High‐Performance Flexible Fiber‐Shaped Ni–Zn Battery based on a Ni–NiO Heterostructured Nanosheet Cathode

Currently, the main bottleneck for the widespread application of Ni-Zn batteries is their poor cycling stability as a result of the irreversibility of the Ni-based cathode and dendrite formation of the Zn anode during the charging-discharging processes. Herein, a highly rechargeable, flexible, fiber-shaped Ni-Zn battery with impressive electrochemical performance is rationally demonstrated by employing Ni-NiO heterostructured nanosheets as the cathode. Benefiting from the improved conductivity and enhanced electroactivity of the Ni-NiO heterojunction nanosheet cathode, the as-fabricated fiber-shaped Ni-NiO//Zn battery displays high capacity and admirable rate capability. More importantly, this Ni-NiO//Zn battery shows unprecedented cyclic durability both in aqueous (96.6% capacity retention after 10 000 cycles) and polymer (almost no capacity attenuation after 10 000 cycles at 22.2 A g-1 ) electrolytes. Moreover, a peak energy density of 6.6 µWh cm-2 , together with a remarkable power density of 20.2 mW cm-2 , is achieved by the flexible quasi-solid-state fiber-shaped Ni-NiO//Zn battery, outperforming most reported fiber-shaped energy-storage devices. Such a novel concept of a fiber-shaped Ni-Zn battery with impressive stability will greatly enrich the flexible energy-storage technologies for future portable/wearable electronic applications.

SnS/SnO heterostructures embedded in porous carbon microcages by boosting charge transfer for enhanced sodium-ion storage

ABSTRACT Currently, tin based materials are widely explored as anode materials for sodium ion batteries due to their high theoretical capacity and large reserves. However, the practical applications of these materials are always hindered by their poor conductivity, slow sodium ion diffusion rate as well as complicated preparation process. Given this, a distinctive hybrid composite consisting of SnS/SnO heterostructures embedded inside multidimensional porous carbon microcages have been successfully synthesized through a facile one-pot method. Benefiting from the fascinating properties at SnS/SnO heterointerfaces, the optimized hybrid electrode yields a remarkable capacity of 274.7 mAh g−1 at 0.5 A g−1 and a good cycling stability with 70.1% capacity retention after 200 cycles. This method can provide inspiration in further innovation of other high-performance SIBs electrodes and create more possibilities for the implementation of large-scale production.

Ultrahigh energy fiber-shaped supercapacitors based on porous hollow conductive polymer composite fiber electrodes

Fiber-shaped supercapacitors (FSCs) that exhibit high electrochemical performance while maintaining mechanical reliability are urgently needed to meet the growing demand for wearable electronics. However, developing fiber electrodes with nanoporous microstructures remains challenging. Here, we proposed high-energy, ultra-stable FSC devices based on a new class of porous, hollow, and conductive composite fibers (PHCFs) with a multilayer structure. The nanoporous structures of the PHCFs substantially increased both the specific surface area (98.1 m2 g−1) and the pore volume (0.43 cm3 g−1), but had a negligible influence on the mechanical properties. Such an interconnected nanoporous structure in the PHCFs guaranteed high mass loading and high efficiency utilization of electrodeposited PANI, and the derived fiber electrodes (PHCFs@PANI) delivered a high areal capacitance of 2723 mF cm−2 and unprecedented ultrastable cycle performance without any capacitance loss over 26 000 cycles. Furthermore, a symmetric FSC (S-FSC) device based on PHCFs@PANI achieved a remarkable energy density of 55.3 μW h cm−2 at a power density of 447 μW cm−2, values far superior to those of most recently reported FSCs. Moreover, the S-FSC was able to withstand various deformations, such as repeated bending, twisting, and knotting, with a nearly invariant capacity.

Recent advances and challenges of stretchable supercapacitors based on carbon materials@@@基于碳材料的可伸缩型超级电容器的研究进展

Stretchable energy storage devices are essential for the development of stretchable electronics that can maintain their electronic performance while sustain large mechanical strain. In this context, stretchable supercapacitors (SSCs) are regarded as one of the most promising power supply in stretchable electronic devices due to their high power densities, fast charge-discharge capability, and modest energy densities. Carbon materials, including carbon nanotubes, graphene, and mesoporous carbon, hold promise as electrode materials for SSCs for their large surface area, excellent electrical, mechanical, and electrochemical properties. Much effort has been devoted to developing stretchable, carbon-based SSCs with different structure/performance characteristics, including conventional planar/textile, wearable fiber-shaped, transparent, and solid-state devices with aesthetic appeal. This review summarizes recent advances towards the development of carbon-based SSCs. Challenges and important directions in this emerging field are also discussed.摘要可伸缩型储能器件的研究对现代电子产品的发展至关重要. 可伸缩型超级电容器(SSCs)能在大的应力应变条件下保持其储能性能不 受损害, 是近年来发展的一种新型、高效、实用的储能装置. 碳纳米管和石墨烯等碳材料由于具有较大的比表面积、优良的导电性和机 械性能优势, 以及突出的电化学性能, 成为伸缩型超级电容器电极材料的新选择. 近年来, 为进一步提高碳基可伸缩型超级电容器的性能, 许多课题组致力于其一维线状、二维平面/网状和三维立体结构的探索研究中. 本篇综述总结了近年来碳基可伸缩型超级电容器的研究策 略和方法, 并通过分析讨论该新兴领域的一些重要挑战, 提出未来可行的研究方向.