当前位置: X-MOL 学术ACS Nano › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
High-Rate Nanostructured Pyrite Cathodes Enabled by Fluorinated Surface and Compact Grain Stacking via Sulfuration of Ionic Liquid Coated Fluorides
ACS Nano ( IF 17.1 ) Pub Date : 2018-12-05 00:00:00 , DOI: 10.1021/acsnano.8b06660
Keyi Chen 1, 2 , Ye Zhang 1, 2 , Chilin Li 1
Affiliation  

Metal-polysulfide batteries are attracting broad attention as conversion reaction systems of high theoretical energy density and low cost. However, their further applications are hindered by the low loading of active species, excess conductive additive, and loose (nanostructured) electrode networkss. Herein, we propose that compact grain stacking and surface fluorination are two crucial factors for achieving high-rate and long-life pyrite (FeS2) cathodes enabled by sulfurating ionic liquid wrapped open-framework fluorides. Both of the factors can accelerate the Li- and Na-driven transport across the pyrite–electrolyte interface and conversion propagation between adjacent grains. Such an electrode design enables a highly reversible capacity of 425 mAh/g after 1000 cycles at 1 C for Li storage and 450 mAh/g after 1200 cycles at 2 C for Na storage, even under a high loading of pyrite grains and ultrathin carbon coating (<2 nm). Its cathode energy density can reach to 800 and 350 Wh/kg for Li and Na cells, respectively, under a high power density of 10000 W/kg. The cross-linkage between ionic liquid and fluoride precursors appears to be a solution to the reinforcement of surface fluorination.

中文翻译:

氟化表面和通过离子液体包覆氟化物的硫化而实现的紧凑晶粒堆积可实现高速纳米结构黄铁矿阴极

金属多硫化物电池作为具有高理论能量密度和低成本的转化反应系统受到了广泛的关注。然而,它们的进一步应用由于活性物质的低负载,过量的导电添加剂和松散的(纳米结构的)电极网络而受到阻碍。在此,我们提出紧凑的晶粒堆积和表面氟化是获得高速率和长寿命黄铁矿(FeS 2)通过硫化包裹包裹的开放式框架氟化物的离子液体而形成的阴极。这两个因素都可以加速锂和钠驱动的黄铁矿-电解质界面之间的传输以及相邻晶粒之间的转换传播。这样的电极设计即使在高负荷的黄铁矿晶粒和超薄碳涂层下,也能在1 C下存储1000次循环后实现425 mAh / g的高可逆容量,而在2 C下进行1200次循环后可存储450 mAh / g。 (<2 nm)。在10000 W / kg的高功率密度下,Li和Na电池的阴极能量密度可以分别达到800和350 Wh / kg。离子液体和氟化物前体之间的交联似乎是增强表面氟化的解决方案。
更新日期:2018-12-05
down
wechat
bug