RESUMEN
All-solid-state lithium-sulfur batteries (ASSLSBs) are considered to be a promising solution for the next generation of energy storage systems due to their high theoretical energy density and improved safety. However, the practical application of ASSLSBs is hindered by several critical challenges, including the poor electrode/electrolyte interface, sluggish electrochemical kinetics of solid-solid conversion between S and Li2S in the cathode, and big volume changes during cycling. Herein, the 85(92Li2S-8P2S5)-15AB composite cathode featuring an integrated structure of a Li2S active material and Li3PS4 solid electrolyte is developed by in situ generating a Li3PS4 glassy electrolyte on Li2S active materials, resulting from a reaction between Li2S and P2S5. The well-established composite cathode structure with an enhanced electrode/electrolyte interfacial contact and highly efficient ion/electron transport networks enables a significant enhancement of redox kinetics and an areal Li2S loading for ASSLSBs. The 85(92Li2S-8P2S5)-15AB composite demonstrates superior electrochemical performance, exhibiting 98% high utilization of Li2S (1141.7 mAh g(Li2S)-1) with both a high Li2S active material content of 44 wt % and corresponding areal loading of 6 mg cm-2. Moreover, the excellent electrochemical activity can be maintained even at an ultrahigh areal Li2S loading of 12 mg cm-2 with a high reversible capacity of 880.3 mAh g-1, corresponding to an areal capacity of 10.6 mAh cm-2. This study provides a simple and facile strategy to a rational design for the composite cathode structure achieving fast Li-S reaction kinetics for high-performance ASSLSBs.
RESUMEN
All-solid-state Li metal batteries (ASSLBs) are currently regarded as one of the most promising next-generation energy storage technologies because of their great potential in realizing both high energy density and safety. However, the development of high performance ASSLBs is still restricted by the large interfacial resistance and Li dendrite propagation within solid electrolytes. Herein, a simple and efficient interfacial modification strategy is proposed to improve the interfacial contact between Li and Li6.4La3Zr1.4Ta0.6O12 (LLZTO) by introducing a uniform and thin Li2Se buffer layer. The Li2Se buffer layer formed by an in situ conversion reaction can not only enhance the wettability of lithium metal toward LLZTO electrolyte but also facilitate uniform lithium plating/stripping. As a result, the interfacial resistance of Li/LLZTO decreased from 270.5 to 5.1 Ω cm2, and the lithium symmetric cell can cycle stably for 350 h at a current density of 0.5 mA cm-2. Meanwhile, the Li|LLZTO-Li2Se|LiNi0.8Co0.1Mn0.1O2 full cells exhibit a high initial capacity of 162.3 mAh g-1 and good cycling stability with a capacity retention of 84.3% after 100 cycles at 0.2 C. These results prove the effectiveness of this modification method and provide new design strategies for the development of high performance ASSLBs.
RESUMEN
In this study, the microwave was employed during the alkaline treatment process, in order to separate the hemicelluloses and cellulose from a delignified hardwood kraft pulp. In relation to hemicelluloses yield, the integrated microwave and alkaline treatment resulted in 9.25% and 12.05% at 50°C and 80°C, respectively. Correspondingly, the resultant pulp fibers presented the increased cellulose content, which was desirable for manufacturing dissolving pulp. Additionally, the effect from mechanical refining pretreatment followed microwave and alkaline treatment, on the separation of hemicelluloses and cellulose, was also investigated.