As ynergistic Nd oping plus PO 4 3À intercalation strategy is used to induce high conversion (ca. 41 %) of 2H-MoS 2 into 1T-MoS 2 ,which is muchhigher than single Ndoping (ca. 28 %) or single PO 4 3À intercalation (ca. 10 %). Ascattering mechanism is proposed to illustrate the synergistic phase transformation from the 2H to the 1T phase,w hich was confirmed by synchrotron radiation and spherical aberration TEM. To further enhance reaction kinetics,t he designed (N,PO 4 3À )-MoS 2 nanosheets are combined with conductive vertical graphene (VG) skeleton forming binder-free arrays for high-efficiency hydrogen evolution reaction (HER). Owing to the decreased band gap,l ower d-band center,a nd smaller hydrogen adsorption/desorption energy,t he designed (N,PO 4 3À )-MoS 2 /VGe lectrode shows excellent HER performance with al ower Tafel slope and overpotential than N-MoS 2 /VG, PO 4 3À -MoS 2 /VGc ounterparts,a nd other Mo-base catalysts in the literature.
Pursuit of advanced batteries with high-energy density is one of the eternal goals for electrochemists. Over the past decades, lithium-sulfur batteries (LSBs) have gained world-wide popularity due to their high theoretical energy density and cost effectiveness. However, their road to the market is still full of thorns. Apart from the poor electronic conductivity of sulfur-based cathodes, LSBs involve special multielectron reaction mechanisms associated with active soluble lithium polysulfides intermediates. Accordingly, the electrode design and fabrication protocols of LSBs are different from those of traditional lithium ion batteries. This review is aimed at discussing the electrode design/fabrication protocols of LSBs, especially the current problems on various sulfur-based cathodes (such as S, Li 2 S, Li 2 S x catholyte, organopolysulfides) and corresponding solutions. Different fabrication methods of sulfur-based cathodes are introduced and their corresponding bullet points to achieve high-quality cathodes are highlighted. In addition, the challenges and solutions of sulfur-based cathodes including active material content, mass loading, conductive agent/binder, compaction density, electrolyte/sulfur ratio, and current collector are summarized and rational strategies are refined to address these issues. Finally, the future prospects on sulfur-based cathodes and LSBs are proposed.
Lithium (Li) metal is considered as one of the most promising anode materials for next‐generation high‐energy‐density storage systems. However, the practical application of Li metal anode is hindered by interfacial instability and air instability due to the highly reactivity of Li metal. Unstable interface in Li metal batteries (LMBs) directly dictates Li dendrite growth, “dead Li” and low Coulombic efficiency, resulting in inferior electrochemical performance of LMBs and even safety issues. In addition, its sensitivity to ambient air leads to the severe corrosion of Li metal anode, high requirements of production and storage, and increased manufacturing cost. Plenty of efforts in recent years have overcome many bottlenecks in these fields and hastened the practical applications of high‐energy‐density LMBs. In this review, we focus on emerging methods of these two aspects to fulfill a stable and low cost electrode. In this perspective, design artificial solid electrolyte interphase (SEI) layers, construct three‐dimensional conductive current collectors, optimize electrolytes, employ solid‐state electrolytes, and modify separators are summarized to be propitious to ameliorate interfacial stability. Meanwhile, ex situ/in situ formed protective layers are highlighted in favor of heightening air stability. Finally, several possible directions for the future research on advanced Li metal anode are addressed.
To meet the growing demand of sophisticated modern electronics and electric vehicles, it is critical to develop advanced battery systems with large energy density. [1][2][3][4] Accordingly, lithium-sulfur batteries (LSBs) have becoming the research Tailored construction of advanced carbon hosts is playing a great role in the development of high-performance lithium-sulfur batteries (LSBs). Herein, a novel N,P-codoped trichoderma spore carbon (TSC) with a bowl structure, prepared by a "trichoderma bioreactor" and annealing process is reported. Moreover, TSC shows excellent compatibility with conductive niobium carbide (NbC), which is in situ implanted into the TSC matrix in the form of nanoparticles forming a highly porous TSC/NbC host. Importantly, NbC plays a dual role in TSC for not only pore formation but also enhancement of conductivity. Excitingly, the sulfur can be well accommodated in the TSC/ NbC host forming a high-performance TSC/NbC-S cathode, which exhibits greatly enhanced rate performance (810 mAh g −1 at 5 C) and long cycling life (937.9 mAh g −1 at 0.1 C after 500 cycles), superior to TSC-S and other carbon/S counterparts due to the larger porosity, higher conductivity, and better synergetic trapping effect for the soluble polysulfide intermediate. The synergetic work of porous the conductive architecture, heterodoped N&P polar sites in TSC and polar conductive NbC provides new opportunities for enhancing physisorption and chemisorption of polysulfides leading to higher capacity and better rate capability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.