Layered transition metal oxides are promising cathode materials for sodium-ion batteries due to their high energy density and appropriate operating potential. However, the poor structural stability is a major drawback to their widespread application. To address this issue, B is successfully introduced into the tetrahedral site of Na Fe Mn O , demonstrating the effectiveness of small-radius ion doping in improving electrochemical performance.
View Article and Find Full Text PDFAs a potential substitute for lithium-ion battery, sodium-ion batteries (SIBs) have attracted a tremendous amount of attention due to their advantages in terms of cost, safety and sustainability. Nevertheless, further improvement of the energy density of cathode materials in SIBs remains challenging and requires the activation of anion redox reaction (ARR) activity to provide additional capacity. Herein, we report a high-performance Mn-based sodium oxide cathode material, NaMgZnMnO (NMZMO), with synergistic activation of ARR by cosubstitution.
View Article and Find Full Text PDFDefect engineering on electrode materials is considered an effective approach to improve the electrochemical performance of batteries since the presence of a variety of defects with different dimensions may promote ion diffusion and provide extra storage sites. However, manipulating defects and obtaining an in-depth understanding of their role in electrode materials remain challenging. Here, we deliberately introduce a considerable number of twin boundaries into spinel cathodes by adjusting the synthesis conditions.
View Article and Find Full Text PDFNi-rich layered cathode materials are considered as promising electrode materials for lithium ion batteries due to their high energy density and low cost. However, the low rate performance and poor electrochemical stability hinder the large-scale application of Ni-rich layered cathodes. In this work, both the rate performance and the structural stability of the Ni-rich layered cathode LiNiCoMnO are significantly improved via the dual-site doping of Nb on both lithium and transition-metal sites, as revealed by neutron diffraction results.
View Article and Find Full Text PDFManipulation of oxygen-related impurities is an extreme challenge for most of the thermoelectric materials, especially for those possessing nanostructures, since they normally result in the degradation of the thermoelectric performance. Here, we demonstrate that by atomic-scale controlling of oxygen doping in the form of dislocation clusters in Bi2Te2.7Se0.
View Article and Find Full Text PDFA boron (B) center, which has an electronic structure mimicking the filled and empty d orbitals in transition metals, can effectively activate the triple bond in N so as to catalyze the nitrogen reduction reaction (NRR). Here, by means of density functional theory, we have systematically investigated the catalytic performance of a single B atom decorated on two-dimensional transition metal carbides (MXenes). The B-doped MoCO and WCO MXenes exhibit outstanding catalytic activity and selectivity with limiting potentials of -0.
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