Conventional ion batteries utilizing metallic ions as the single charge carriers are limited by the insufficient abundance of metal resources. Although supercapacitors apply both cations and anions ...to store energy through absorption and/or Faradic reactions occurring at the interfaces of the electrode/electrolyte, the inherent low energy density hinders its application. The graphite‐cathode‐based dual‐ion battery possesses a higher energy density due to its high working potential of nearly 5 V. However, such a battery configuration suffers from severe electrolyte decomposition and exfoliation of the graphite cathode, rendering an inferior cycle life. Herein, a new surface‐modification strategy is developed to protect the graphite cathode from the anion salvation effect and the deposition derived from electrolyte decomposition by generating an artificial solid electrolyte interphase (SEI). Such SEI‐modified graphite exhibits superior cycling stability with 96% capacity retention after 500 cycles under 200 mA g−1 at the upper cutoff voltage of 5.0 V, which is much improved compared with the pristine graphite electrode. Through several ex situ studies, it is revealed that the artificial SEI greatly stabilizes the interfaces of the electrode/electrolyte after reconstruction and gradual establishment of the optimal anion‐transport path. The findings shed light on a new avenue toward promoting the performance of the dual‐ion battery (DIB) and hence to make it practical finally.
An artificial layer of a solid electrolyte interphase is fabricated on a graphite cathode for a dual‐ion battery (DIB). Such surface modification can alleviate the electrolyte decomposition at the high working voltage of the anion de‐/intercalation processes and the solvation effect of anions, much improving the cycling stability of the Li//graphite DIB.
Hard carbon is regarded as a promising anode material for sodium‐ion batteries (SIBs). However, it usually suffers from the issues of low initial Coulombic efficiency (ICE) and poor rate performance, ...severely hindering its practical application. Herein, a flexible, self‐supporting, and scalable hard carbon paper (HCP) derived from scalable and renewable tissue is rationally designed and prepared as practical additive‐free anode for room/low‐temperature SIBs with high ICE. In ether electrolyte, such HCP achieves an ICE of up to 91.2% with superior high‐rate capability, ultralong cycle life (e.g., 93% capacity retention over 1000 cycles at 200 mA g−1) and outstanding low‐temperature performance. Working mechanism analyses reveal that the plateau region is the rate‐determining step for HCP with a lower electrochemical reaction kinetics, which can be significantly improved in ether electrolyte.
A self‐supporting, flexible, additive‐free and scalable hard carbon paper (HCP) derived from tissue is rationally developed, and it achieves outstanding Na‐storage properties in terms of high initial Coulombic efficiency (91.2%), superior high‐rate capability, ultralong cyclic stability, as well as outstanding low‐T performance in ether electrolyte. More significantly, the Na‐storage and capacity attenuation mechanism of the HCP anode is revealed.
Adsorption data of helium on activated carbon at low temperatures are essential for its use in sorption coolers, gas-gap heat switches and the regenerators of cryocoolers. Especially when an ...activated carbon is used as the regenerator material in a cryocooler, the high specific heat caused by the high amount of adsorbed helium is expected to solve the bottleneck problem that the conventional 4 K cryocooler regenerator material suffers. It also has the advantage of being non-magnetic. However, the amounts of helium adsorbed on on the activated carbon in the temperature range of 4–10 K are low. In this paper, the adsorption isotherms of helium on a coconut shell-based activated carbon in the pressure-temperature range (4–10 K, 0.5–3.5 MPa) were measured with a self-built adsorption apparatus, from which the isosteric heats of adsorption and the specific heats of the activated carbon with adsorbed helium were calculated. The helium flow resistance through the activated carbon was also measured to evaluate its feasibility in a cryocooler. Results indicate that the isotherms are type I and can be fitted by the Langmuir adsorption model. The isosteric heats of adsorption are around 279 J/mol and change little with the amount of adsorbed helium. The specific heats of the activated carbon with adsorbed helium depend on the adsorption temperature and pressure, and their average values at 4–10 K are the highest among the commonly used solid regenerator materials (lead, SS, Er3Ni and HoCu2) and gaseous helium under the pressures investigated, which are ascribed to the high amount of helium adsorbed and the high heat of adsorption of helium on the activated carbon. The helium flow resistance through a material is related to its size and surface roughness and the value through the activated carbon is moderate among the four commonly used solid regenerator materials. Activated carbon with adsorbed helium is suitable as a regenerator material of cryocoolers because of its high specific heat and moderate flow resistance.
In the extensive application processes of lithium ion batteries (LIBs), a great quantity of spent LIBs is producing, which is harmful to human and the environment if not handled properly. In ...addition, due to the scarcity of lithium on earth, sodium with relatively high abundance and low cost is expected to replace lithium. Hence, it is an interesting and urgent work of reusing the spent materials from the end-of-life LIBs for designing sodium-ion batteries (SIBs). Herein, an efficient method is proposed to recycle the spent LiMn2O4 and directly reuse it as the cathode of SIBs. As electrochemical tests show, such recycled LiMn2O4 delivers excellent Na-storage properties in SIBs. For example, its discharge capacity can gradually increase to 163.2 mAh g−1 over 50 cycles at 100 mA g−1, and the highest reversible capacity is up to 176.3 mAh g−1 at 20 mA g−1. It is further revealed by combining the electrochemical analyses and ex-situ characterizations that, the continuous increase of capacity during the initial 50 cycles is due to the phase transition of the spinel into layered structure caused by the Li+/Na+ (de)insertion. Studies of electrode kinetics indicate the faster ion diffusion in the layered material than the spinel one. This work provides a new strategy to recycle the spent LIBs, i.e., directly reusing the exhausted electrode materials to the next-generation batteries.
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•A simple and efficient method is proposed to recycle the spent LiMn2O4.•Recycled LiMn2O4 can be directly used as cathode for sodium ion batteries (SIBs).•Recycled LiMn2O4 delivers excellent electrochemical properties in SIBs.•A series of tests reveal the phase evolution process during the initial 50 cycles.•Electrode kinetics is analyzed and discussed by the electrochemical studies.
A carbon-incorporated LiMnBO3/boron oxide composite (LMB/BxOy@C) is prepared as an advanced anode material for lithium-ion batteries (LIBs). The prepared LMB/BxOy@C can deliver a reversible capacity ...of about 362.5 mAh g−1 at a low current density of 0.04 A g−1. When cycled at 2.0 A g−1, the specific capacity increases from 159.7 mAh g−1 at the 100th cycle to 263.3 mAh g−1, which still maintains at 259 mAh g−1 after 1000 cycles. The excellent cycling performance and boosting effect of capacity should be due to the existence of conductive carbon network, the inactive boron oxide to provide outstanding structural stability, and the activation of the transformation between Mn2+ and Mn4+ during cycling. The preliminary result illustrates that the prepared LMB/BxOy@C could be a promising anode material for LIBs.
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•A carbon-incorporated LiMnBO3/boron oxide composite is prepared controllably.•The synthetic route has low cost and simple operation.•The optimized anode material exhibits excellent cycle life.•The optimized anode shows superior kinetic performance.
In article number 1903125, Xing‐Long Wu, and co‐workers report a self‐supporting, flexible, additive‐free, and scalable hard carbon paper derived from tissue, which achieves outstanding Na‐storage ...properties in terms of high initial Coulombic efficiency (91.2%), superior high‐rate capability, ultralong cyclic stability, and outstanding low‐T performance. In addition, its Na‐storage and capacity attenuation mechanism are also revealed.
Owing to the high de/intercalation potential of anions on graphite cathode, dual-ion battery (DIB) has attracted much attention for advanced energy storage. Among various DIBs, Li//graphite (Li//G) ...configuration delivers the highest voltage to achieve the theoretically highest energy density due to the lowest Li-plating/-stripping potential. Unfortunately, the dendrite nature of Li anode brings a series of serious problems, fatally restricting the practical application of Li//G DIB. Herein, we for the first time propose fabricating artificial and robust a solid electrolyte interphase layer on Li anode to suppress Li dendritic growth during cycling and hence to improve the cyclic stability of Li//G DIB. As a result, a long-life Li//G DIB is assembled and achieved successfully with the enhanced and smoothed Coulombic efficiencies (CE). For example, the Li//G DIB exhibits a high capacity retention of 89.6% with an average CE of 97.8% and initial discharge capacity of 95.2 mAh g–1 over 500 cycles at 1 A g–1. This study points out a new possible strategy to enhance the energy-storage performance of Li//G DIB with high practicability.
Objective This study was aimed to investigate the toxic effects of 3 nanomaterials, i.e. multi-walled carbon nanotubes （MWCNTs）, graphene oxide （GO）, and reduced graphene oxide （RGO）, on zebrafish ...embryos. Methods The 2-h post-fertilization （hpf） zebrafish embryos were exposed to MWCNTs, GO, and RGO at different concentrations （1, 5, 10, 50, 100 mg/L） for 96 h. Afterwards, the effects of the 3 nanomateria on spontaneous movement, heart rate, hatching rate, length of larvae, mortality, and malformations Is were evaluated. Results Statistical analysis indicated that RGO significantly inhibited the hatching of zebrafish embryos. Furthermore, RGO and MWCNTs decreased the length of the hatched larvae at 96 hpf. No obvious morphological malformation or mortality was observed in the zebrafish embryos after exposure to the three nanomaterials. Conclusion MWCNTs, GO, and RGO were all toxic to zebrafish embryos to influence embryos hatching and larvae length. Although no obvious morphological malformation and mortality were observed in exposed zebrafish embryos, further studies on the toxicity of the three nanomaterials are still needed.
In a study, the adsorption isotherms of helium on a coconut shell-based activated carbon in the pressure-temperature range (4-10 K, 0.5-3.5 MPa) were measured with a self-built adsorption apparatus, ...from which the isosteric heats of adsorption and the specific heats of the activated carbon with adsorbed helium were calculated. The helium flow resistance through the activated carbon was also measured to evaluate its feasibility in a cryocooler. Results indicate that the isotherms are type I and can be fitted by the Langmuir adsorption model.
A carbon-incorporated LiMnBO3/boron oxide composite (LMB/BxOy@C) is prepared as an advanced anode material for lithium-ion batteries (LIBs). The prepared LMB/BxOy@C can deliver a reversible capacity ...of about 362.5 mAh g−1 at a low current density of 0.04 A g−1. When cycled at 2.0 A g−1, the specific capacity increases from 159.7 mAh g−1 at the 100th cycle to 263.3 mAh g−1, which still maintains at 259 mAh g−1 after 1000 cycles. The excellent cycling performance and boosting effect of capacity should be due to the existence of conductive carbon network, the inactive boron oxide to provide outstanding structural stability, and the activation of the transformation between Mn2+ and Mn4+ during cycling. The preliminary result illustrates that the prepared LMB/BxOy@C could be a promising anode material for LIBs.
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