Synthesis of Co-Ni oxide microflowers as a superior anode for hybrid supercapacitors with ultralong cycle life

Li-ion hybrid capacitors (LIHCs), composing of a lithium-ion battery (LIB) type anode and a supercapacitor (SC) type cathode, gained worldwide popularity due to harmonious integrating the virtues of high energy density of LIBs with high power density of SCs. Herein, nanoflakes composed microflower-like Co-Ni oxide (CoNiO) was successfully synthesized by a simple co-precipitation method. The atomic ratio of as-synthesized CoNiO is determined to be 1:3 through XRD and XPS analytical method. As a typical battery-type material, CoNiO and capacitor-type activated polyanilinederived carbon (APDC) were used to assemble LIHCs as the anode and cathode materials, respectively. As a result, when an optimized mass ratio of CoNiO and APDC was 1:2, CoNiO//APDC LIHC could deliver a maximum energy density of 143 Wh kg^-1 at a working voltage of 1-4 V. It is worth mentioning that the LIHC also exhibits excellent cycle stability with the capacitance retention of 78.2% after 15,000 cycles at a current density of 0.5 A g^-1.     

长寿命、高倍率(Li4Ti5O12-AC)/( LiMn2O4-AC)电池电容的制备及性能研究

以商业微米级锰酸锂(LiMn2O4)为正极,钛酸锂(Li4Ti5O12)为负极,分别与商业活性炭(AC)复合,组装成软包装电池电容样品并进行电化学测试。测试结果表明：当样品正负极均复合AC时,其电化学性能要优于只有正极复合AC和未复合AC的样品。其中,正负极活性炭复合比例为5 wt.%,负极与正极的理论容量比(N/P)为1.01时,电池电容样品拥有良好的倍率性能,且其在0.5 C时的放电比容量为56.4 mAh/g,5 C时的容量保持率为0.5 C的72.2%。此外,与未复合AC的样品相比,单体在5 C倍率下经2000次循环后的容量保持率仍有77.5%,远高于前者的30.4%。     

Electrolyte Solvation Manipulation Enables Unprecedented Room-Temperature Calcium-Metal Batteries

Calcium-metal batteries (CMBs) provide a promising option for high-energy and cost-effective energy-storage technology beyond the current state-of-the-art lithium-ion batteries. Nevertheless, the development of room-temperature CMBs is significantly impeded by the poor reversibility and short lifespan of the calcium-metal anode. A solvation manipulation strategy is reported to improve the plating/stripping reversibility of calcium-metal anodes by enhancing the desolvation kinetics of calcium ions in the electrolyte. The introduction of lithium salt changes the electrolyte structure considerably by reducing coordination number of calcium ions in the first solvation shell. As a result, an unprecedented Coulombic efficiency of up to 99.1 % is achieved for galvanostatic plating/stripping of the calcium-metal anode, accompanied by a very stable long-term cycling performance over 200 cycles at room temperature. This work may open up new opportunities for development of practical CMBs.     

Agar-derived nitrogen-doped porous carbon as anode for construction of cost-effective lithium-ion batteries

Balancing cost and performance of porous carbon (PC) as anode for lithium-ion battery (LIBs) is the key to effectively promote commercial application. Herein, low-cost N-doped PC (NPC-Ts, T = 600, 750 and 900 °C) were facilely prepared in batches via one-pot pyrolysis of agar with different carbonization temperature. The NPC-750 with specific surface area of 2914 m²/g and N content of 2.84% exhibits an ultrahigh reversible capacity of 1019 mAh/g at 0.1 A/g after 100 cycles and 837 mAh/g at 1 A/g after 500 cycles. Remarkably, the resulting LIBs exhibit an ultrafast charge-discharge feature with a remarkable capacity of 281 mAh/g at 10 A/g and a superlong cycle life with a capacity retention of 87% after 5000 cycles at 10 A/g. Coupling with LiFePO₄ cathode, the fabricated lithium-ion full cells possess high capacity, excellent rate and cycling performances (125 mAh/g at 100 mA/g, capacity retention of 95%, after 220 cycles), highlighting the practicability of this NPC-750 as the anode materials.     

High-Voltage Rechargeable Alkali–Acid Zn–PbO2 Hybrid Battery

Aqueous rechargeable batteries have attracted attention owning to their advantages of safety, low cost, and sustainability, while the limited electrochemical stability window (1.23 V) of water leads to their failure in competition with organic-based lithium-ion batteries. Herein, we report an alkali–acid Zn–PbO₂ hybrid aqueous battery obtained by coupling an alkaline Zn anode with an acidic PbO₂ cathode. It shows the capability to deliver an impressively high open-circuit voltage (V_oc) of 3.09 V and an operate voltage of 2.95 V at 5 mA cm⁻², thanks to the contribution of expanding the voltage window and the electrochemical neutralization energy from the alkali–acid asymmetric-electrolyte hybrid cell. The hybrid battery can potentially deliver a large area capacity over 2 mAh cm⁻² or a high energy density of 252.39 Wh kg⁻¹ and shows almost no fading in area capacity over 250 charge–discharge cycles.     

Large-scale synthesis of ultrathin hexagonal tin disulfide nanosheets with highly reversible lithium storage

Ultrathin hexagonal SnS(2) nanosheets are synthesized via a simple hydrothermal reaction. The nanosheets have been applied as an anode for lithium-ion battery, which shows highly reversible capacity and good cycling stability with excellent capacity retention of 96% after 50 cycles.     

超级电容电池

本文比较了超级电容器、锂离子电池和超级电容电池的结构、原理、研究现状和发展前景。超级电容电池的正极具有超级电容器电极的结构和双电层储能机制,负极具有类似锂离子电池负极的结构和快速电化学储能机制。超级电容器和锂离子电池的发展空间都很有限,而作为两者结合的产物的超级电容电池可兼具高比功率、高比能量、高放电电压和长循环寿命的优点,是未来储能电池的发展方向之一,但还面临缺乏具有高分解电压的电解液和高充电电压下电解液中离子枯竭的问题。     

Conduction of Li+ cations in ethylene carbonate (EC) and propylene carbonate (PC): comparative studies using density functional theory

Density functional theory is used to study the interaction of Li⁺ cation with ethylene carbonate (EC) and propylene carbonate (PC) comparatively, which are the most popular solvents used in lithium-ion battery composite. In our theoretical calculations, we use DFT hybrid parameter B3LYP5 with a basis set 6–31G** by means of PCGAMESS/Firefly software package. We analyze the optimized structures of EC, PC, and their clusters including lithium-ion. We then calculate solvation energy, desolvation energy, electron affinity, Gibbs free energy, heats of formation of Li⁺ solvated by EC and PC, and the charge on Li⁺. From the above analysis, we observe EC as a better solvent than PC in applications of lithium-ion batteries.     

气相色谱-串联质谱法同时测定锂离子电池电解液中13种有机磷阻燃剂的含量

建立了一种可同时测定锂离子电池电解液中13种有机磷阻燃剂含量的气相色谱-串联质谱分析方法,以乙酸乙酯为萃取溶剂,超声萃取锂离子电池电解液中的有机磷阻燃剂,萃取液经浓缩、定容、过滤后进行气相色谱-串联质谱分析,外标法定量。结果显示,13种有机磷阻燃剂在一定浓度范围内线性良好,相关系数不低于0.999 3,方法的检出限(S/N=3)为0.3~30μg/kg,定量下限(S/N=10)为1~100μg/kg。在低、中、高3个加标水平下的平均回收率为80.4%~94.6%,相对标准偏差(RSD)为3.8%~10%。该方法简单快捷,灵敏度高,定量下限低,可满足锂离子电池电解液中有机磷阻燃剂含量日常检测需要。     

Forced-air cooling system for large-scale lithium-ion battery modules during charge and discharge processes

Journal of Thermal Analysis and Calorimetry - Heat generation and accumulation during working schemes of the lithium-ion battery (LIB) are the critical safety issues in hybrid electric vehicles or...     

基于局部最小二乘支持向量机的光谱定量分析

提出了一种基于局部最小二乘支持向量机(LSSVM)的回归方法,以克服待测参数和光谱数据间的非线性。本方法首先通过欧式距离选取局部训练样本子集,然后利用该子集建立LSSVM校正模型。由于每个测试样本建模时要选取不同的训练样本,因此提出相对距离的概念用来改进高斯核函数,使LSSVM的参数对于不同的训练样本具有自调整功能。针对一批汽油样本的实验结果表明,本方法的预测精度优于常见的局部线性建模方法和全局建模方法。     

Influence of solvent type on porosity structure and properties of polymer separator for the Li-ion batteries

Polyethylene-supported polymethyl methacrylate/poly(vinylidene fluoride-co-hexafluoropropylene) separator for gel polymer lithium-ion battery use was prepared with a mixed solvent of n-butanol and acetone. The prepared separator was characterized with scanning electron spectroscopy and X-ray diffraction, and its performance was investigated by electrochemical impedance spectroscopy and battery charge/discharge test. Compared to the separator prepared with acetone, the separator prepared with the mixed solvent shows an enhanced porosity (from 42 to 49 %) and electrolyte uptake (from 104 to 125 %). The ionic conductivity of the corresponding gel polymer electrolyte is improved from 2.81 to 3.39 mS cm^?1, the discharge capacity retention of the LiCoO₂/artificial graphite battery is increased from 95 to 98 % after 100 cycles at 0.5 C, and the discharge capacity of the battery at 1 C increases by 4 %.     

基于机器学习方法的丙型肝炎病毒聚合酶NS5B非核苷抑制剂的定量构效关系研究

对89 个苯并异噻唑和苯并噻嗪类丙型肝炎病毒(HCV) NS5B聚合酶非核苷抑制剂进行了定量构效关系(QSAR)研究. 采用遗传算法组合偏最小二乘(GA-PLS)和线性逐步回归分析(LSRA)两种特征选择方法选择最优描述符子集, 然后建立多元线性回归和偏最小二乘线性回归模型. 并首次尝试使用遗传算法耦合支持向量机方法(GA-SVM)对两种特征选择方法所选的描述符子集分别建立非线性支持向量机回归模型. 三种机器学习方法所建模型均得到比较满意的预测效果. 采用LSRA所选的6 个描述符建立的三个QSAR模型对于测试集的相关系数为0.958-0.962, GA-SVM法给出最好的预测精度(0.962). 采用GA-PLS所选的7个描述符建立的三个QSAR模型对于测试集的相关系数为0.918-0.960, 偏最小二乘回归模型的结果最好(0.960). 本工作提供了一种有效的方法来预测丙型肝炎病毒抑制剂的生物活性, 该方法也可以扩展到其他类似的定量构效关系研究领域.     

Improved lithium cyclability and storage in mesoporous SnO2 electronically wired with very low concentrations (≤1 %) of reduced graphene oxide

On the wire: Mesoporous tin dioxide (SnO(2)) wired with very low amounts (≤1?%) of reduced graphene oxide (rGO) exhibits a remarkable improvement in lithium-ion battery performance over bare mesoporous or solid nanoparticles of SnO(2). Reversible lithium intercalation into SnO(2)/SnO over several cycles was demonstrated in addition to conventional reversible lithium storage by an alloying reaction.     

电化学储能研究22年回顾

本文回顾了22年来作者的电化学储能研究活动,共分三个部分. 第一部分叙述高比能量、高比功率储能器件研究,包括锂硫电池研究（硫复合正极材料、锂硫电池制作、锂硼合金作为锂硫电池负极、硫-锂离子电池新体系）、超级电容器研究（超级活性炭、以酚醛树脂为原料制备电容炭、碳纳米管阵列中寄生准电容储能材料、氧化镍干凝胶准电容储能材料、归纳出电容炭材料的性能要求、电容器研制、确定“第四类”超级电容器）、锂离子电池研究（锂离子电池与可再生燃料电池的对决、双变价元素正极材料、磷酸钴锂正极材料、高功率锂离子电池的制作）. 第二部分叙述规模储能电池研究,包括液流电池新体系研究（蓄电与电化学合成的双功能液流电池、全金属化合物单液流电池、有机化合物正极的单液流电池）、致力于振兴铅酸电池（推广铅蓄电池新技术、铅炭电池的研究、铅酸电池新型板栅的研究）,储能电池（站）的经济效益计算方法. 第三部分叙述电动汽车发展路线研究,包括氢能燃料电池电动汽车、纯电动汽车与混合动力汽车、对我国电动汽车发展路线的建议、力争电动汽车补贴的合理化、坚守电动汽车“节能减排”宗旨、提出“发电直驱电动车”. 最后的结束语谈了三点感悟.