ABSTRACT
Phlomoides is one of the largest genera of Lamiaceae with approximately 150-170 species distributed mainly in Eurasia. In this study, we describe and illustrate a new species, P.henryi, which was previously misidentified as P.bracteosa, from Yunnan Province, southwest China. Molecular phylogenetic analyses revealed that P.henryi is found within a clade in which most species lack basal leaves. In this clade, the new species is morphologically distinct from P.rotata in having an obvious stem and, from the rest, by having transparent to white trichomes inside the upper corolla lip. In addition, micro-features of trichomes on the calyx and leaf epidermis can differentiate the new species from other species grouped in the same clade and a key, based on trichome morphology for these species, is provided. The findings demonstrate that the use of scanning electron microscopy can reveal inconspicuous morphological affinities amongst morphologically similar species and play an important role in the taxonomic study of the genus Phlomoides.
ABSTRACT
Manganese oxide is a promising cathode material for rechargeable aqueous zinc-ion batteries (ZIBs). However, the low electronic conductivity and unstable structure evolution of manganese materials often result in poor rate performance and rapid capacity decay. Herein, we design N-doped Na2Mn3O7 (N-NMO) by combining sodium preintercalation and nitridation treatment strategies to stabilize the crystalline structure and reaction interface. Sodium preintercalation not only enlarges the interlayer distance for fast Zn2+ ion diffusion but also serves as a robust pillar to stabilize the crystalline structure during cycling. Meanwhile, the nitridation layer on the surface of Na2Mn3O7 particles is favorable for enhancing the electronic conductivity and inhibiting the cathode dissolution issue during repeated cycling. Consequently, the as-prepared N-NMO exhibits high reversible capacity (300 mAh g-1 at 0.2 A g-1), good rate capability (100 mAh g-1 at 10 A g-1), and outstanding long-term cycling stability (high capacity retention of 78.9% after 550 cycles at 2 A g-1). Considering the facile and simple synthesizing methods, the synergistic engineering of the interlayer structure and interface is expected to provide new opportunities for the development of high-performance Mn-based cathode materials for aqueous ZIBs.
ABSTRACT
The indumentum of nutlets is shown to be of phylogenetic importance in previous molecular phylogenetic studies of Paraphlomis, a genus of Lamiaceae with approximately 30 species distributed mainly in southern China and Southeast Asia. Nearly half the species of Paraphlomis are known from limestone areas. In this study, we described and illustrated a new species, P.hsiwenii, from the karst mountain forests in Guangxi Zhuang Autonomous Region, China. Our molecular phylogenetic analyses revealed that P.hsiwenii is recovered in a clade consisting of species with hairy nutlets. The new species is morphologically most similar to P.pagantha from the same clade, but they differ in the morphology of lamina bases, length of pedicels and calyces, as well as the morphology of upper corolla lips.
ABSTRACT
Although Li-metal anodes are extremely attractive owing to the ultrahigh theoretical specific capacity, the low Coulombic efficiency and severe safety hazards resulting from uncontrollable Li dendrites growth hinder their widespread implementation. Herein, we propose a novel design of Ni macropore arrays for the functional Li deposition host. Benefiting from the regulated electric field distribution, Li nucleation and growth can be well confined within conductive Ni macropores. Consequently, the Ni macropore array electrode exhibits stable Li deposition behavior, i.e., high Coulombic efficiency of above 97% over 400 cycles for 1.0 mAh cm-2. Most importantly, the LiFePO4 || Li-Ni macropore arrays full cell also shows greatly enhanced cycling stability (90.3 mAh g-1 at 1 C after 700 cycles), holding great promise for high-performance rechargeable Li metal batteries.
ABSTRACT
Developing advanced high-rate electrode materials has been a crucial aspect for next-generation lithium ion batteries (LIBs). A conventional nanoarchitecturing strategy is suggested to improve the rate performance of materials but inevitably brings about compromise in volumetric energy density, cost, safety, and so on. Here, micro-size Nb14 W3 O44 is synthesized as a durable high-rate anode material based on a facile and scalable solution combustion method. Aberration-corrected scanning transmission electron microscopy reveals the existence of open and interconnected tunnels in the highly crystalline Nb14 W3 O44 , which ensures facile Li+ diffusion even within micro-size particles. In situ high-energy synchrotron XRD and XANES combined with Raman spectroscopy and computational simulations clearly reveal a single-phase solid-solution reaction with reversible cationic redox process occurring in the NWO framework due to the low-barrier Li+ intercalation. Therefore, the micro-size Nb14 W3 O44 exhibits durable and ultrahigh rate capability, i.e., ≈130 mAh g-1 at 10 C, after 4000 cycles. Most importantly, the micro-size Nb14 W3 O44 anode proves its highest practical applicability by the fabrication of a full cell incorporating with a high-safety LiFePO4 cathode. Such a battery shows a long calendar life of over 1000 cycles and an enhanced thermal stability, which is superior than the current commercial anodes such as Li4 Ti5 O12 .