Ameliorating the interfacial issues of all-solid-state lithium metal batteries by constructing polymer/inorganic composite electrolyte

Lithium metal is one of the most promising anodes for next-generation batteries due to its high capacity and low reduction potential.However,the notorious Li dendrites can cause the short life span and safety issues,hindering the extensive application of lithium batteries.Herein,Li_(7)La_(3)Zr_(2)O_(12)(LLZO)ceramics are integrated into polyethylene oxide(PEO)to construct a facile polymer/inorganic composite solid-state electrolyte(CSSE)to inhibit the growth of Li dendrites and widen the electrochemical stability window.Given the feasibility of our strategy,the designed PEO-LLZO-LiTFSI composite solid-state electrolyte(PLLCSSE)exhibits an outstanding cycling property of 134.2 mAh g^(-1) after 500 cycles and the Coulombic efficiency of 99.1%after 1000 cycles at 1 C in LiFePO_(4)-Li cell.When cooperated with LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode,the PLL-CSSE renders a capacity retention of 82.4%after 200 cycles at 0.2 C.More importantly,the uniform dispersion of LLZO in PEO matrix is tentative tested via Raman and FT-IR spectra and should be responsible for the improved electrochemical performance.The same conclusion can be drawn from the interface investigation after cycling.This work presents an intriguing solid-state electrolyte with high electrochemical performance,which will boost the development of all-solid-state lithium batteries with high energy density.

超纯无烟煤导电性影响因素

为研究无烟煤自身的导电特性,提高其导电性能,使无烟煤成为填料和电极材料的一部分,采用酸溶法制备了灰分0.13%的超纯无烟煤,采用粉末电阻率仪探索了含水率、灰分、压强、粒度及矿物质成分对超纯无烟煤导电性的影响规律。结果表明,无烟煤电导率随含水率和压强的升高呈上升趋势。随灰分降低电导率逐渐升高。灰分低于1.0%时,电导率随灰分降低而急剧升高。压强4.00 MPa、含水率6.21%、粒度0.2~0.1 mm,灰分降至0.13%时,无烟煤导电性最佳,其电导率为1.44×10^(-7)S/cm。研究范围内,粒度对无烟煤电导率影响较小。煤中常见矿物质的电导率顺序为:黄铁矿>高岭石>二氧化硅>碳酸钙>硫酸钙;黄铁矿电导率最高,达1.32×10^(-2)S/cm。无烟煤电导率随黄铁矿含量增加呈升高趋势,而随其他矿物质含量增加呈降低趋势。采用响应曲面模型优化正交试验结果,获得了无烟煤电导率与含水率、灰分及粒度之间的二次回归方程。含水率和灰分对无烟煤电导率测试结果的影响显著,其中灰分对电导率的影响程度最大,含水率次之,粒度最小。

澳大利亚某锂辉石矿浮选试验研究

澳大利亚某锂多金属矿Li_(2)O含量1.51%,脉石矿物主要为石英、云母和钠长石。针对该矿在磨矿细度-0.074mm占75%左右,采用新型捕收剂Q,通过预除云母+一粗一精一扫的浮选闭路流程,最终获得Li_(2)O品位6.52%,回收率89.89%的锂辉石精矿,实现该矿中锂辉石矿物的充分富集。同时,脱出的云母产品纯度高,可作为本方案的附加产品,经分选后,得到精矿产品中有用组分Ta_(2)O_(5)品位0.0985%、回收率69.87%,Nb_(2)O_(5)品位0.0337%、回收率73.81%,可为后续综合回收与利用钽铌提供合适原料。