A Sustainable Solid Electrolyte Interphase for High-Energy-Density Lithium Metal Batteries Under Practical Conditions

High-energy-density Li metal batteries suffer from a short lifespan under practical conditions, such as limited lithium, high loading cathode, and lean electrolytes, owing to the absence of appropriate solid electrolyte interphase (SEI). Herein, a sustainable SEI was designed rationally by combining fluorinated co-solvents with sustained-release additives for practical challenges. The intrinsic uniformity of SEI and the constant supplements of building blocks of SEI jointly afford to sustainable SEI. Specific spatial distributions and abundant heterogeneous grain boundaries of LiF, LiN_xO_y, and Li₂O effectively regulate uniformity of Li deposition. In a Li metal battery with an ultrathin Li anode (33 μm), a high-loading LiNi_0.5Co_0.2Mn_0.3O₂ cathode (4.4 mAh cm⁻²), and lean electrolytes (6.1 g Ah⁻¹), 83 % of initial capacity retains after 150 cycles. A pouch cell (3.5 Ah) demonstrated a specific energy of 340 Wh kg⁻¹ for 60 cycles with lean electrolytes (2.3 g Ah⁻¹).     

Electrolyte Regulation towards Stable Lithium-Metal Anodes in Lithium–Sulfur Batteries with Sulfurized Polyacrylonitrile Cathodes

Lithium–sulfur (Li–S) batteries are highly regarded as the next-generation energy-storage devices because of their ultrahigh theoretical energy density of 2600 Wh kg⁻¹. Sulfurized polyacrylonitrile (SPAN) is considered a promising sulfur cathode to substitute carbon/sulfur (C/S) composites to afford higher Coulombic efficiency, improved cycling stability, and potential high-energy-density Li–SPAN batteries. However, the instability of the Li-metal anode threatens the performances of Li–SPAN batteries bringing limited lifespan and safety hazards. Li-metal can react with most kinds of electrolyte to generate a protective solid electrolyte interphase (SEI), electrolyte regulation is a widely accepted strategy to protect Li-metal anodes in rechargeable batteries. Herein, the basic principles and current challenges of Li–SPAN batteries are addressed. Recent advances on electrolyte regulation towards stable Li-metal anodes in Li–SPAN batteries are summarized to suggest design strategies of solvents, lithium salts, additives, and gel electrolyte. Finally, prospects for future electrolyte design and Li anode protection in Li–SPAN batteries are discussed.     

氰基桥联的Fe2Ni2单分子磁体的合成与磁性

利用三氰基构筑单元Bu₄N[Fe^Ⅲ（PzTp）（CN）₃]（PzTp=tetrakis（pyrazolyl）borate）和4,4''-二甲氧基-2,2''-联吡啶（4,4''-dmobpy）配体,合成了2例氰基桥联的Fe^Ⅲ₂Ni^Ⅱ₂四核配合物。单晶X射线衍射表明化合物[Fe^Ⅲ（PzTp）（CN）₃]₂[Ni^Ⅱ₂（4,4''-dmobpy）₄][Fe^Ⅲ（PzTp）（CN）₃]₂·2CH₃OH（1）和[Fe^Ⅲ（PzTp）（CN）₃]₂[Ni^Ⅱ₂（4,4''-dmobpy）₄]（PF₆）₂（2）具有四核四方形分子结构。直流磁化率测试表明配合物1和2均表现为分子内的铁磁耦合作用。交流磁化率测试表明配合物1和2在零场下具有慢磁弛豫行为,有效能垒分别为12.8和13.0 K。     

Homotopic method of solving a class of EI Nino/La Nina-Southern Oscillation sea-air oscillator

The EI Nino/La Nina-Southern Oscillation （ENSO） is an interannual phenomenon involved in the tropical Pacific Ocean-atmosphere interactions. In this paper, an asymptotic method of solving the nonlinear equation for the ENSO model is created. And based on a class of oscillator of the ENSO model, the approximate solution of a corresponding problem is studied by employing the method of homotopic mapping. It is proved from the results that the homotopic method can be used for analysing the sea surface temperature anomaly in the equatorial eastern Pacific and the thermocline depth anomaly of the atmosphere-ocean oscillation for the ENSO model.     

Stability of Tokamak Equilibrium with Internal Transport Barrier against High-n MHD Ballooning Mode

A new eigen-mode equation for the tokamak high-n （the toroidal mode number） ideal magnetohydrodynamic （MHD） ballooning mode in tokamak plasmas is derived to include the toroidal effects that are significant for stability of configurations with internal transport barriers （ITBs）, Fot tokamak equilibria of shift circular flux surfaces, these toroidal effects basically are the finite inverse aspect ratio and the Shafranov shift. The former yields the averaged favorable curvature stabilization while the latter further strengthens this effect, leading to a low shear stable channel connecting the first and second stability regions, and to the shrinkage of unstable region in the （8,α） diagram. The dependence of the critical shear, below which the plasma is stable, on these effects is given. These results are important for understanding the ITB physics to some regards.     

一个非线性方程的渐近激波解

该文是利用简捷的方法得到了高精度的非线性问题渐近激波解。     

扰动Vakhnenko方程物理模型的行波解

研究了一类扰动Vakhnemko方程.给出了改进的渐近方法.首先, 对原模型系统对应的典型方程得到对应的行波解.其次, 引入一个泛函, 建立迭代关系式,将求解非线性问题转化为求解一系列的迭代序列.然后, 逐次地求出对应的解的近似式, 最后,得到了原扰动Vakhnemko模型行波解的任意次精度的近似展开式,并讨论了它的精度. 关键词： 泛函 行波解 Vakhnemko方程     

一类非线性扰动发展方程的广义迭代解

利用广义变分迭代方法研究了一类非线性发展扰动方程.首先引入一个泛函.然后求其变分,最后构造方程解的迭代关系式.得到了问题的近似解和精确解析解. 关键词： 发展方程 扰动 变分迭代     

非化学计量比靶材溅射制备Cu-Al-O薄膜的光学电学性质研究

考虑到铜铝溅射速率的差别,使用铜铝比例为0.9 ∶1的多晶CuAlO₂靶材,用射频磁控溅射法制备Cu-Al-O薄膜.研究不同衬底温度对薄膜光学电学性能的影响.在衬底温度500 ℃附近,薄膜在可见光范围内具有很好的透光性,达到70%,计算拟合得到直接帯隙为3.52 eV,与CuAlO₂相的理论值符合较好.在室温附近,薄膜导电符合半导体热激活机理,在衬底温度为500 ℃附近薄膜电导率达到2.48×10^-3 S·cm^-1. 关键词： Cu-Al-O 衬底温度 透过率 电导率     

掺氮四面体非晶碳的第一性原理研究

采用基于第一性原理的分子动力学方法对掺氮四面体非晶碳进行结构建模,并对其显微结构和电子结构进行了研究. 氮在非晶碳网络中的配位形态与密度没有明显关系,主要是以三配位形态存在,其次是两配位,四配位氮的比例很小. 掺氮后碳网络结构sp²含量大大增加,随着氮含量的增加,费米能级附近态密度增加. 氮掺入后并未使费米能级发生明显移动. 关键词： 掺氮四面体非晶碳 第一性原理 密度泛函理论 电子结构