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Ruding Zhang Jiajia Huang Wenzhuo Deng Jingze Bao Yilong Pan Shuping Huang Chuan‐Fu Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(46):16626-16631
A key challenge for potassium‐ion batteries is to explore low‐cost electrode materials that allow fast and reversible insertion of large‐ionic‐size K+. Here, we report an inorganic‐open‐framework anode (KTiOPO4), which achieves a reversible capacity of up to 102 mAh g?1 (307 mAh cm?3), flat voltage plateaus at a safe average potential of 0.82 V (vs. K/K+), a long lifespan of over 200 cycles, and K+‐transport kinetics ≈10 times faster than those of Na‐superionic conductors. Combined experimental analysis and first‐principles calculations reveal a charge storage mechanism involving biphasic and solid solution reactions and a cell volume change (9.5 %) even smaller than that for Li+‐insertion into graphite (≈10 %). KTiOPO4 exhibits quasi‐3D lattice expansion on K+ intercalation, enabling the disintegration of small lattice strain and thus high structural stability. The inorganic open‐frameworks may open a new avenue for exploring low‐cost, stable and fast‐kinetic battery chemistry. 相似文献
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Emmanuel Picheau Ferdinand Hof Alain Derr Barbara Daffos Alain Pnicaud 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(45):16159-16163
Kinetic data, for example, activation energy and reaction order, are crucial for the understanding of chemical reactions and processes. Here, we describe a novel method for obtaining kinetic data based on thermogravimetric measurements (TGA) that exploits in each measurement multiple successive isothermal steps (SIS). We applied this method to the notoriously challenging carbon combustion process for vastly different carbons for oxygen molar fractions between 1.4 % and 90 %. Our obtained apparent EA values are within the wide range of results in the literature and vary in a systematic way with the oxygen partial pressure. The improved accuracy and large amount of obtainable data allowed us to show that the majority of experimentally obtained apparent data for apparent EA are neither in a kinetic regime nor in a diffusion‐controlled one but rather in a transition regime. 相似文献
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