Next‐generation batteries based on conversion reactions, including aqueous metal–air batteries, nonaqueous alkali metal‐O2 and ‐CO2 batteries, alkali metal‐chalcogen batteries, and alkali metal‐ion ...batteries have attracted great interest. However, their use is restricted by inefficient reversible conversion of active agents. Developing bifunctional catalysts to accelerate the conversion reaction kinetics in both discharge and charge processes is urgently needed. Graphene‐, or graphene‐like carbon‐supported atomically dispersed metal catalysts (G‐ADMCs) have been demonstrated to show excellent activity in various electrocatalytic reactions, making them promising candidates. Different from G‐ADMCs for catalysis, which only require high activity in one direction, G‐ADMCs for rechargeable batteries should provide high activity in both discharging and charging. This review provides guidance for the design and fabrication of bifunctional G‐ADMCs for next‐generation rechargeable batteries based on conversion reactions. The key challenges that prevent their reversible conversion, the origin of the activity of bifunctional G‐ADMCs, and the current design principles of bifunctional G‐ADMCs for highly reversible conversion, have been analyzed and highlighted for each conversion‐type battery. Finally, a summary and outlook on the development of bifunctional G‐ADMC materials for next‐generation batteries with a high energy density and excellent energy efficiency are given.
This review analyzes the key factors that hinder the reversible conversion of conversion‐type materials, provides a fundamental understanding of graphene‐, or graphene‐like carbon‐supported atomically dispersed metal catalysts (G‐ADMCs), and provides guidance on the bifunctional G‐ADMCs to be used in high‐performance next‐generation batteries, including aqueous metal–air batteries, nonaqueous alkali metal‐O2 and ‐CO2 batteries, alkali metal‐chalcogen batteries, and alkali metal‐ion batteries.
Single‐atom metal catalysts (SACs) are used as sulfur cathode additives to promote battery performance, although the material selection and mechanism that govern the catalytic activity remain ...unclear. It is shown that d‐p orbital hybridization between the single‐atom metal and the sulfur species can be used as a descriptor for understanding the catalytic activity of SACs in Li–S batteries. Transition metals with a lower atomic number are found, like Ti, to have fewer filled anti‐bonding states, which effectively bind lithium polysulfides (LiPSs) and catalyze their electrochemical reaction. A series of single‐atom metal catalysts (Me = Mn, Cu, Cr, Ti) embedded in three‐dimensional (3D) electrodes are prepared by a controllable nitrogen coordination approach. Among them, the single‐atom Ti‐embedded electrode has the lowest electrochemical barrier to LiPSs reduction/Li2S oxidation and the highest catalytic activity, matching well with the theoretical calculations. By virtue of the highly active catalytic center of single‐atom Ti on the conductive transport network, high sulfur utilization is achieved with a low catalyst loading (1 wt.%) and a high area‐sulfur loading (8 mg cm−2). With good mechanical stability for bending, these 3D electrodes are suitable for fabricating bendable/foldable Li–S batteries for wearable electronics.
A descriptor, the d–p hybridization state between single‐atom metal catalysts (SACs) and sulfur species, is proposed to guide the design of SACs for Li–S batteries. The large‐sized and flexible 3D electrodes with optimized SACs achieve high specific energy with low catalyst loading and high sulfur loading. The good mechanical stability for bending also shows potential for fabricating bendable/foldable Li–S batteries.
Lithium‐sulfur (Li‐S) batteries have attracted tremendous interest because of their high theoretical energy density and cost effectiveness. The target of Li‐S battery research is to produce batteries ...with a high useful energy density that at least outperforms state‐of‐the‐art lithium‐ion batteries. However, due to an intrinsic gap between fundamental research and practical applications, the outstanding electrochemical results obtained in most Li‐S battery studies indeed correspond to low useful energy densities and are not really suitable for practical requirements. The Li‐S battery is a complex device and its useful energy density is determined by a number of design parameters, most of which are often ignored, leading to the failure to meet commercial requirements. The purpose of this review is to discuss how to pave the way for reliable Li‐S batteries. First, the current research status of Li‐S batteries is briefly reviewed based on statistical information obtained from literature. This includes an analysis of how the various parameters influence the useful energy density and a summary of existing problems in the current Li‐S battery research. Possible solutions and some concerns regarding the construction of reliable Li‐S batteries are comprehensively discussed. Finally, insights are offered on the future directions and prospects in Li‐S battery field.
The research status of Li‐S batteries is briefly reviewed based on statistical analysis results. A summary of existing problems in the current Li‐S battery research is concluded with possible solutions and some concerns comprehensively discussed. Perspectives are proposed with respect to more reliable lithium‐sulfur batteries with rationally improved performance.
Sodium‐ion batteries (SIBs) based on conversion‐type metal sulfide (MS) anodes have attracted extraordinary attention due to relatively high capacity and intrinsic safety. The highly reversible ...conversion of M/Na2S to pristine MS in charge plays a vital role with regard to the electrochemical performance. Here, taking conventional MoS2 as an example, guided by theoretical simulations, a catalyst of iron single atoms on nitrogen‐doped graphene (SAFe@NG) is selected and first used as a substrate to facilitate the reaction kinetics of MoS2 in the discharging process. In the following charging process, using a combination of spectroscopy and microscopy, it is demonstrated that the SAFe@NG catalyst enables an efficient reversible conversion reaction of Mo/Na2S→NaMoS2→MoS2. Moreover, theoretical simulations reveal that the reversible conversion mechanism shows favorable formation energy barrier and reaction kinetics, in which SAFe@NG with the Fe–N4 coordination center facilitates the uniform dispersion of Na2S/Mo and the decomposition of Na2S and NaMoS2. Therefore, efficient reversible conversion reaction MoS2↔NaMoS2↔Mo/Na2S is enabled by the SAFe@NG catalyst. This work contributes new avenues for designing conversion‐type materials with an efficient reversible mechanism.
A catalyst of iron single atoms on a nitrogen‐doped graphene (SAFe@NG) substrate is selected to catalyze reversible conversion in MoS2 anodes. Importantly, the SAFe@NG catalyst with highly active Fe–N4 sites significantly facilitates the conversion of Mo/Na2S to MoS2 in the charging processes, resulting in an efficient reversible conversion reaction of MoS2↔NaMoS2↔Mo/Na2S in a complete cycle, which is demonstrated by spectroscopy, microscopy, and simulations.
The complement system is highly activated in primary membranous nephropathy (MN). Identifying the complement components that damage podocytes has important therapeutic implications. This study ...investigated the role of C3a and the C3a receptor (C3aR) in the pathogenesis of MN.
C3aR expression in kidneys and circulating levels of C3a of MN patients were examined. Human podocyte damage was assessed after exposure to MN plasma +/- C3aR blockade (SB290157, JR14a). C3aR antagonists were administered to rats with Heymann nephritis on day 0 or after proteinuria. Clinical and pathologic parameters, specific IgG and complement activation, and podocyte injuries were then assessed.
In the glomeruli, C3aR staining merged well with podocin. Overexpression of C3aR correlated positively with proteinuria, serum creatinine, and no response to treatments. Human podocytes exposed to MN plasma showed increased expression of PLA2R, C3aR, and Wnt3/
-catenin, reduced expression of synaptopodin and migration function, downregulated Bcl-2, and decreased cell viability. C3aR antagonists could block these effects. In Heymann nephritis rats, C3aR blockade attenuated proteinuria, electron-dense deposition, foot process width, and glomerular basement membrane thickening in glomeruli. The increased plasma C3a levels and overexpression of C3aR were also alleviated. Specific, but not total, IgG levels decreased, with less deposition of rat IgG in glomeruli and subsequent reduction of C1q, factor B, and C5b-9.
C3a anaphylatoxin is a crucial effector of complement-mediated podocyte damage in MN. The C3aR antagonist may be a potentially viable treatment for this disease.
As a rapidly growing family of 2D transition metal carbides and nitrides, MXenes are recognized as promising materials for the development of future electronics and optoelectronics. So far, the ...reported patterning methods for MXene films lack efficiency, resolution, and compatibility, resulting in limited device integration and performance. Here, a high‐performance MXene image sensor array fabricated by a wafer‐scale combination patterning method of an MXene film is reported. This method combines MXene centrifugation, spin‐coating, photolithography, and dry‐etching and is highly compatible with mainstream semiconductor processing, with a resolution up to 2 µm, which is at least 100 times higher than other large‐area patterning methods reported previously. As a result, a high‐density integrated array of 1024‐pixel Ti3C2Tx/Si photodetectors with a detectivity of 7.73 × 1014 Jones and a light–dark current ratio (Ilight/Idark) of 6.22 × 106, which is the ultrahigh value among all reported MXene‐based photodetectors, is fabricated. This patterning technique paves a way for large‐scale high‐performance MXetronics compatible with mainstream semiconductor processes.
MXenes are promising for future electronics and optoelectronics; however, previously reported patterning methods lack efficiency, resolution, and compatibility with mainstream semiconductor processing. Here, a wafer‐scale combination patterning method with a resolution up to the micrometer scale is developed, resulting in an integrated array of 1024‐pixel Ti3C2Tx/Si photodetectors with a record‐high detectivity of 7.73 × 1014 Jones.
0D/2D heterojunctions, especially quantum dots (QDs)/nanosheets (NSs) have attracted significant attention for use of photoexcited electrons/holes due to their high charge mobility. Herein, ...unprecedent heterojunctions of vanadate (AgVO3, BiVO4, InVO4 and CuV2O6) QDs/graphitic carbon nitride (g‐C3N4) NSs exhibiting multiple unique advances beyond traditional 0D/2D composites have been developed. The photoactive contribution, up‐conversion absorption, and nitrogen coordinating sites of g‐C3N4 NSs, highly dispersed vanadate nanocrystals, as well as the strong coupling and band alignment between them lead to superior visible‐light‐driven photoelectrochemical (PEC) and photocatalytic performance, competing with the best reported photocatalysts. This work is expected to provide a new concept to construct multifunctional 0D/2D nanocomposites for a large variety of opto‐electronic applications, not limited in photocatalysis.
Vanadate quantum dots including AgVO3, BiVO4, InVO4, and CuV2O6 were strongly coupled with graphitic carbon nitride nanosheets using an in situ growth strategy. These quantum dots displayed a much better visible‐light‐driven photoelectrochemical activity and photocatalytic degradation efficiency than single vanadate quantum dots, carbon nitride nanosheets or previously reported highly active photocatalysts.
Sulfur electrodes based on a 3D integrated hollow carbon fiber foam (HCFF) are synthesized with high sulfur loadings of 6.2–21.2 mg cm−2. Benefiting from the high electrolyte absorbability of the ...HCFF and the multiple conductive channels, the obtained electrode demonstrates excellent cycling stability and a high areal capacity of 23.32 mAh cm−2, showing great promise in commercially viable Li–S batteries.
Summary Background End-stage kidney disease is a leading cause of morbidity and mortality worldwide. Prevalence of the disease and worldwide use of renal replacement therapy (RRT) are expected to ...rise sharply in the next decade. We aimed to quantify estimates of this burden. Methods We systematically searched Medline for observational studies and renal registries, and contacted national experts to obtain RRT prevalence data. We used Poisson regression to estimate the prevalence of RRT for countries without reported data. We estimated the gap between needed and actual RRT, and projected needs to 2030. Findings In 2010, 2·618 million people received RRT worldwide. We estimated the number of patients needing RRT to be between 4·902 million (95% CI 4·438–5·431 million) in our conservative model and 9·701 million (8·544–11·021 million) in our high-estimate model, suggesting that at least 2·284 million people might have died prematurely because RRT could not be accessed. We noted the largest treatment gaps in low-income countries, particularly Asia (1·907 million people needing but not receiving RRT; conservative model) and Africa (432 000 people; conservative model). Worldwide use of RRT is projected to more than double to 5·439 million (3·899–7·640 million) people by 2030, with the most growth in Asia (0·968 million to a projected 2·162 million 1·571–3·014 million). Interpretation The large number of people receiving RRT and the substantial number without access to it show the need to both develop low-cost treatments and implement effective population-based prevention strategies. Funding Australian National Health and Medical Research Council.
Single‐atom catalysts (SACs) are the smallest entities for catalytic reactions with projected high atomic efficiency, superior activity, and selectivity; however, practical applications of SACs ...suffer from a very low metal loading of 1–2 wt%. Here, a class of SACs based on atomically dispersed transition metals on nitrogen‐doped carbon nanotubes (MSA‐N‐CNTs, where M = Ni, Co, NiCo, CoFe, and NiPt) is synthesized with an extraordinarily high metal loading, e.g., 20 wt% in the case of NiSA‐N‐CNTs, using a new multistep pyrolysis process. Among these materials, NiSA‐N‐CNTs show an excellent selectivity and activity for the electrochemical reduction of CO2 to CO, achieving a turnover frequency (TOF) of 11.7 s−1 at −0.55 V (vs reversible hydrogen electrode (RHE)), two orders of magnitude higher than Ni nanoparticles supported on CNTs.
A novel atomically dispersed transition‐metal single‐atom catalyst supported on carbon nanotubes is synthesized with atomic loading as high as 20 wt%, excellent selectivity, and activity for the electrochemical reduction of carbon dioxide.
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