Designing ionic channels in novel carbons for electrochemical energy storage

Tremendous efforts have been dedicated to developing high-performance energy storage devices based onthe micro- or nano-manipulation of novel carbon electrodes, as certain nanocarbons are perceived to haveadvantages such as high specific surface areas, superior electric conductivities, excellent mechanicalproperties and so on. In typical electrochemical electrodes, ions are intercalated/deintercalated into/fromthe bulk (for batteries) or adsorbed/desorbed on/from the surface (for electrochemical capacitors). Fastionic transport, significantly determined by ionic channels in active electrodes or supporting materials, is aprerequisite for the efficient energy storage with carbons. In this report, we summarize recent designstrategies for ionic channels in novel carbons and give comments on the promising features based on thosecarbons towards tailorable ionic channels

Direct Laser Writing of Graphene Made from Chemical Vapor Deposition for Flexible, Integratable Micro-Supercapacitors with Ultrahigh Power Output

High‐performance yet flexible micro‐supercapacitors (MSCs) hold great promise as miniaturized power sources for increasing demand of integrated electronic devices. Herein, this study demonstrates a scalable fabrication of multilayered graphene‐based MSCs (MG‐MSCs), by direct laser writing (DLW) of stacked graphene films made from industry‐scale chemical vapor deposition (CVD). Combining the dry transfer of multilayered CVD graphene films, DLW allows a highly efficient fabrication of large‐areal MSCs with exceptional flexibility, diverse planar geometry, and capability of customer‐designed integration. The MG‐MSCs exhibit simultaneously ultrahigh energy density of 23 mWh cm−3 and power density of 1860 W cm−3 in an ionogel electrolyte. Notably, such MG‐MSCs demonstrate an outstanding flexible alternating current line‐filtering performance in poly(vinyl alcohol) (PVA)/H2SO4 hydrogel electrolyte, indicated by a phase angle of −76.2° at 120 Hz and a resistance–capacitance constant of 0.54 ms, due to the efficient ion transport coupled with the excellent electric conductance of the planar MG microelectrodes. MG–polyaniline (MG‐PANI) hybrid MSCs fabricated by DLW of MG‐PANI hybrid films show an optimized capacitance of 3.8 mF cm−2 in PVA/H2SO4 hydrogel electrolyte; an integrated device comprising MG‐MSCs line filtering, MG‐PANI MSCs, and pressure/gas sensors is demonstrated

Charge Storage Mechanisms of Single-Layer Graphene in Ionic Liquid

Graphene-based carbon materials are promising candidates for electrical double-layer (EDL) capacitors, and there is considerable interest in understanding the structure and properties of the graphene/electrolyte interface. Here, electrochemical impedance spectroscopy (EIS) and electrochemical quartz crystal microbalance (EQCM) are used to characterize the ion fluxes and adsorption on single-layer graphene in neat ionic liquid (EMI-TFSI) electrolyte. It is found that a positively charged ion-species desorption and ion reorganization dominate the double-layer charging during positive and negative polarizations, respectively, leading to the increase in EDL capacitance with applied potential

Heteroatoms (O, N)-Doped Porous Carbon Derived From Bamboo Shoots Shells For High Performance Supercapacitors

Activated carbon derived from plant wastes is attractive for the fabrication of low cost and high performance electrochemical energy storage devices. The heteroatoms (O, N)-doped porous carbon (KAC-700) is fabricated from bamboo shoots shells via KOH activation. The symmetric supercapacitor based on KAC-700 has gravimetric and volumetric capacitance of 223.21 F g−1 and 167.63 F cm−3, respectively, at current density of 1 A g−1 in 1 M H2SO4 electrolyte. This supercapacitor also delivers a high energy density of 13.15 Wh kg−1 at power density of 546.60 W kg−1 in 1 M Na2SO4 electrolyte, as well as high capacitance retention rate of 93.62% after 4000 cycles at 5 A g−1. Compared with graphene, carbon nanotubes and other expensive carbon material, this activated carbon has a bright future due to its low cost and easy fabrication process as electrode material for supercapacitors

Hierarchical Porous Carbon With High Nitrogen Content Derived From Plant Waste (Pomelo Peel) For Supercapacitor

The plant waste pomelo peels are used as carbon precursors to fabricate nitrogen-doped hierarchical porous carbon. The sample PC600 is fabricated at mild calcination temperature of 600 °C, which has nitrogen content of as high as 4.47% and hierarchical pores with a BET surface area of 1104 m2 g−1. The symmetric supercapacitor based on PC600//PC600 electrodes exhibits excellent electrochemical performance benefiting from both the electric double-layer capacitance and pseudocapacitance of PC600. In 1 M H2SO4 electrolyte, this supercapacitor delivers gravimetric capacitance of 208.7 F g−1, volumetric capacitance of 219.3 F cm−3, and energy density of 7.3 Wh kg−1 at a current density of 1 A g−1. Furthermore, the extraordinary energy density of 21.6 Wh kg−1 at 1 A g−1 and 17.1 Wh kg−1 at 20 A g−1 are obtained in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) electrolyte. The suitable calcination process can make the contents of nitrogen atoms and pores structures in PC600 to achieve an optimal combination, leading to improved electrochemical performance

Numerical Study of the Impact of Complex Terrain and Soil Moisture on Convective Initiation

The relative importance of topography and soil moisture on the initiation of an afternoon deep convection under weak synoptic-scale forcing was investigated using the weather research and forecasting (WRF) model with high resolution (1.33 km). The convection occurred on 29 June 2017, over the Liupan Mountains, west of the Loess Plateau. The timing and location of the convective initiation (CI) simulated by the WRF model compared well with the radar observations. It showed that the warm and humid southerly airflow under 700 hPa was divided into east and west flows due to the blockage of the Liupan Mountains. The warm and humid air on the west side was forced to climb along the slope and enhanced the humidity near the ridge. The accumulation of unstable energy in the middle and north of the ridge led to a strong vertical convergence and triggered the convection. Sensitivity experiments showed that terrain played a dominant role in triggering the convection, while the spatial heterogeneity of soil moisture played an indirect role by affecting the local circulation and the partition of surface energy

Spatial Justice and Residents’ Policy Acceptance: Evidence from Construction Land Reduction in Shanghai, China

Nowadays, the contradiction between strict construction land supply restriction and excessive construction land demand is extremely prominent. Construction land reduction (CLR) is a policy innovation for economically developed regions designed to solve the tight constraints of the construction land quota as urban development continues in China, however, it leads to a lack of spatial justice. In this study, we address a gap in land use regulation literature regarding regional economic development in fast-developing nations by presenting a quantitative investigation of spatial justice in Shanghai, China. We theoretically analyze the connotation of spatial justice in CLR and its influence on residents’ policy acceptance of CLR. Based on theoretical analysis and using household questionnaires from JJ Town in W District, Shanghai, China, we investigate how spatial justice affects residents’ policy acceptance of CLR through an ordered probit model. The results show that (1) spatial justice strengthens residents’ policy acceptance of CLR; (2) both policy familiarity and participation are important influencing factors that contribute to residents’ policy acceptance of CLR; (3) age, education, household income, the contracting land scale and household population structure also affect residents’ policy acceptance of CLR. (4) Robustness tests support the above findings. Thus, in the process of CLR, it is essential to fully consider the realization of spatial justice to ensure the development of remote suburbs, especially the regions experiencing a net reduction in their construction land

PALB2 Links BRCA1 and BRCA2 in the DNA-Damage Response

SummaryBRCA1 and BRCA2 are often mutated in familial breast and ovarian cancer. Both tumor suppressors play key roles in the DNA-damage response [1, 2]. However, it remains unclear whether these two tumor suppressor function together in the same DNA-damage response pathway. Here, we show that BRCA1 associates with BRCA2 through PALB2/FANCN, a major binding partner of BRCA2 [3]. The interaction between BRCA1 and BRCA2 is abrogated in PALB2-deficient Fanconi anemia cells and in the cells depleted of PALB2 by small interfering RNA. Moreover, we show that BRCA1 promotes the concentration of PALB2 and BRCA2 at DNA-damage sites and the interaction between BRCA1 and PALB2 is important for the homologous recombination repair. Taken together, our results indicate that BRCA1 is an upstream regulator of BRCA2 in the DNA-damage response, and PALB2 is the linker between BRCA1 and BRCA2

Soil Moisture-Boundary Layer Feedbacks on the Loess Plateau in China Using Radiosonde Data with 1-D Atmospheric Boundary Layer Model

The Loess Plateau is one land-atmosphere coupling hotspot. Soil moisture has an influence on atmospheric boundary layer development under specific early-morning atmospheric thermodynamic structures. This paper investigates the sensitivity of atmospheric convection to soil moisture conditions over the Loess Plateau in China by using the convective triggering potential (CTP)—humidity index (HIlow) framework. The CTP indicates atmospheric stability and the HIlow indicates atmospheric humidity in the low-level atmosphere. By comparing the model outcomes with the observations, the one-dimensional model achieves realistic daily behavior of the radiation and surface heat fluxes and the mixed layer properties with appropriate modifications. New CTP-HIlow thresholds for soil moisture-atmosphere feedbacks are found in the Loess Plateau area. By applying the new thresholds with long-time scales sounding data, we conclude that negative feedback is dominant in the north and west portion of the Loess Plateau; positive feedback is predominant in the south and east portion. In general, this framework has predictive significance for the impact of soil moisture on precipitation. By using this new CTP-HIlow framework, we can determine under what atmospheric conditions soil moisture can affect the triggering of precipitation and under what atmospheric conditions soil moisture has no influence on the triggering of precipitation

Soil Moisture-Boundary Layer Feedbacks on the Loess Plateau in China Using Radiosonde Data with 1-D Atmospheric Boundary Layer Model

The Loess Plateau is one land-atmosphere coupling hotspot. Soil moisture has an influence on atmospheric boundary layer development under specific early-morning atmospheric thermodynamic structures. This paper investigates the sensitivity of atmospheric convection to soil moisture conditions over the Loess Plateau in China by using the convective triggering potential (CTP)—humidity index (HIlow) framework. The CTP indicates atmospheric stability and the HIlow indicates atmospheric humidity in the low-level atmosphere. By comparing the model outcomes with the observations, the one-dimensional model achieves realistic daily behavior of the radiation and surface heat fluxes and the mixed layer properties with appropriate modifications. New CTP-HIlow thresholds for soil moisture-atmosphere feedbacks are found in the Loess Plateau area. By applying the new thresholds with long-time scales sounding data, we conclude that negative feedback is dominant in the north and west portion of the Loess Plateau; positive feedback is predominant in the south and east portion. In general, this framework has predictive significance for the impact of soil moisture on precipitation. By using this new CTP-HIlow framework, we can determine under what atmospheric conditions soil moisture can affect the triggering of precipitation and under what atmospheric conditions soil moisture has no influence on the triggering of precipitation