溶液组分对铝阳极氧化多孔膜界面电性能的影响

采用电渗法研究了电解质溶液组分对铝阳极氧化多孔膜层界面电性能的影响。结果表明，多孔膜分别经含Ｆ＾－，ＰＯ＾３－４，ＳｉＯ＾２－３或单宁酸溶液浸泡处理后，膜在０．０１ｍｏｌ／ＬＫＣｌ溶液中等电点由原来的ｐＨＩＥＰ＝９．２０分别移至ｐＨＩＥＰ＝３．４０，４．３０，３．３０display structure     

（CeO2）0.7—x（MO）x（La2O3）0.3（M=Mg,Ca,Sr）固体电解质及其性能的…

合成了（ＣｅＯ２）０．７－ｘ（ＭＯ）ｘ（Ｌａ２Ｏ３）０．３（Ｍ－Ｍｇ、Ｃａ、Ｓｒ）固体电解质。对其晶体结构、电导率、ＸＰＳ谱、离子迁移数及制成的燃料电池的Ｖ－Ｉ曲线进行了测定。（ＣｅＯ２）０．７（Ｌａ２Ｏ３）０．３中掺入Ｃａ＾２＋、Ｍｇ＾２＋或Ｓｒ＾２＋，可使电解质的氧离子导电性能改善，从而使制成的燃料电池的开路电压输出功率也得到提高。     

（CeO_2）_（0．7－x）（MO）_x（La_2O_3）_（0．3）（M＝

合成了（ＣｅＯ＿２）＿（０．７－ｘ）（ＭＯ）＿ｘ（Ｌａ＿２Ｏ＿３）＿（０．３）（Ｍ＝Ｍｇ、Ｃａ、Ｓｒ）固体电解质。对其晶体结构、电导率、ＸＰＳ谱、离子迁移数及制成的燃料电池的Ｖ－Ｉ曲线进行了测定。（ＣｅＯ＿２）＿（０．７）（Ｌａ＿２Ｏ＿３）＿（０．３）中掺入Ｃａ￣（２＋）、Ｍｇ￣（２＋）或Ｓｒ￣（２＋），可使电解质的氧离子导电性能改善，从而使制成的燃料电他的开路电压输出功率也得到提高。     

ErCl_3－CaCl_2－LiCl三元体系相图的研究

利用ＤＴＡ研究了ＥｒＣｌ_３ＣａＣｌ_２ＬｉＣｌ三元体系相图。发现该相图有对应于ＥｒＣｌ_３、ＣａＣｌ_２、ＬｉＣｌ和Ｌｉ_３ＥｒＣｌ_６的４个液相面，５条二次结晶线，一个三元低共熔点Ｅ（５８．５％ＥｒＣｌ_３，２３．７％ＣａＣｌ_２，１７．８％ＬｉＣｌ，３９７℃），一个三元转熔点Ｐ（５２．５％ＥｒＣｌ_３，２７．２％ＣａＣｌ_２，２０．３％ＬｉＣｌ，４２８℃）。相应的４相平衡反应为：Ｌ＝ＥｒＣｌ_３＋Ｌｉ_３ＥｒＣｌ_６＋ＣａＣｌ_２；Ｌ＋ＬｉＣｌ＝Ｌｉ_３ＥｒＣｌ_６＋ＣａＣｌ_２．     

SOLID STATE SYNTHESIS AND CRYSTAL STRUCTURE OF THE CLUSTER COMPOUND［MwS_4Cu_3（PPh_3）_3Cl］（Mw＝0，56W＋0．44M0）

ＳＯＬＩＤ　ＳＴＡＴＥ　ＳＹＮＴＨＥＳＩＳ　ＡＮＤ　ＣＲＹＳＴＡＬ　ＳＴＲＵＣＴＵＲＥ　ＯＦ　ＴＨＥ　ＣＬＵＳＴＥＲ　ＣＯＭＰＯＵＮＤ［ＭｗＳ_４Ｃｕ_３（ＰＰｈ_３）_３Ｃｌ］（Ｍｗ＝０，５６Ｗ＋０．４４Ｍ０）ＳＯＬＩＤＳＴＡＴＥＳＹＮＴＨＥＳＩＳＡＮ...     

OZONOLYSIS OF 4－ISOPROPYLIDENEPENTACYCLO（5．4．0．0~（2，6）．0~（3，10）．0~（5，9））UNDECANE－8，11－DIONE

ＯＺＯＮＯＬＹＳＩＳＯＦ４－ＩＳＯＰＲＯＰＹＬＩＤＥＮＥＰＥＮＴＡＣＹＣＬＯ（５．４．０．０￣（２，６）．０￣（３，１０）．０￣（５，９））ＵＮＤＥＣＡＮＥ－８，１１－ＤＩＯＮＥ￥ＪｉａｎＧｕａｎｇＳＵＮ；ＺｈｕａｎｇＳＵ；ＹｏｎｇＺｈｏｎｇＹＵ（Ｃ...     

四元交互体系Li~＋，K~＋／Cl~－，SO_4~（2－）－H_2O50，7

采用等温溶解平衡法测定了四元交互体系Ｌｉ～＋，Ｋ～＋／Ｃｌ～－，７５℃的溶解度和平衡溶液的物化性质（密度、粘度、折光率）．该四元交互体系５０，７５℃的溶解度等温图有５个相区：即Ｌｉ＿２ＳＯ＿４·Ｈ＿２Ｏ，ＫＬｉＳＯ＿４，ＫＣｌ，Ｋ＿２ＳＯ＿４，ＬｉＣｌ·Ｈ＿２Ｏ，７条单变量曲线，３个共饱点，其中Ｌｉ＿２Ｏ＿４·Ｈ）２Ｏ＋ＫＣｌ＋ＬｉＣｌ·Ｈ＿２Ｏ为一致零变量点。用我们以往提出的经验公式处理了平衡溶液的密度和折光率，由所测得的溶解度数据，求得了高温和高锂浓度下的电解质溶液Ｐｉｔｚｅｒ模型的离子相互作用参数。计算了各平衡溶液中盐的活度和水的活度。还计算了该四元交互体系２５℃的溶解度，考察了Ｐｉｔｚｅｒ电解质溶液理论在水－盐溶解度计算中的应用。     

YbCl3—CaCl2—NaCl三元体系相图的研究

借助ＤＴＡ研究了ＹｂＣｌ３－ＣａＣｌ２－ＮａＣｌ三元体系相图，发现该体系有对应于ＹｂＣｌ３、ＣａＣｌ２，Ｎａ３ＹｂＣｌ６的４个液相面，５条二次结晶线，１个三元低共熔点Ｅ（８７．０％ＹｂＣｌ３，１．０％ＣａＣＬ２，１２．０％ＮａＣＬ；４５０℃）和三元转熔点Ｐ（６１．０％ＹｂＣｌ３，１９．０％ＣａＣｌ２，２０．０％ＮａＣｌ；４７４℃）。     

YbCl_3－CaCl_2－NaCl三元体系相图的研究

借助ＤＴＡ研究了ＹｂＣｌ３－ＣａＣｌ２－ＮａＣｌ三元体系相图，发现该体系有对应于ＹｂＣｌ３、ＣａＣｌ２、ＮａＣｌ、Ｎａ３ＹｂＣｌ６的４个液相面，５条二次结晶线，１个三元低共熔点Ｅ（８７．０％ＹｂＣｌ３，１．０％ＣａＣｌ２，１２．０％ＮａＣｌ；４５０℃）和三元转熔点Ｐ（６１．０％ＹｂＣｌ３，１９．０％ＣａＣｌ２，２０．０％ＮａＣ１；４７４℃）。     

［La（EO_3）_3（H_2O）］（ClO_4）_3·H_2O的晶体结构

稀土高氯酸盐开环冠醚三缩乙二醇（ＥＯ_３）［Ｌａ（Ｃ_６Ｈ_（１４）Ｏ_４）_３（Ｈ_２Ｏ）］（ＣｌＯ_４）_３·Ｈ_２Ｏ，单斜晶系，Ｐ２_１／ｃ空间群。晶胞参数为：ａ＝１５．４７４（２），ｂ＝１１．３８６（１），ｃ＝２０．８４１（４），β＝９９．８２（１）°，Ｖ＝３６１８（１），ＭｏＫα，Ｚ＝４，Ｄ_ｃ＝１．７１８ｇ／ｃｍ３，μ＝１．４９９ｍｍ￣（－１）。全矩阵最小二乘精细修正，结构因子Ｒ＝０．０５６，Ｒ_ｗ＝０．０８３。中心原子Ｌａ与开环冠醚醚链上的Ｏ（１）～Ｏ（９）及一个水分子形成１０配位双帽四方反棱柱结构。弱配体高氯酸根不参加配位。     

Monitoring the mechanical properties of the solid electrolyte interphase(SEI) using electrochemical quartz crystal microbalance with dissipation

Stable solid electrolyte interphase(SEI) has been well established to be critical for the reversible operation of Li(ion) batteries,yet our understanding of its mechanical properties currently remains incomplete.Here,we used an electrochemical quartz crystal microbalance combined with dissipation monitoring(EQCM-D) to investigate SEI formation.By quantitatively estimating in-situ,the change in mass,shear modulus,and viscosity of the SEI,we show that the SEI formation in propylene carbonate(PC)-and ethylene carbonate/diethyl carbonate(EC/DEC)-based electrolytes involves the growth of a rigid laye r followed by a viscoelastic layer,whereas a distinct "one-layer" rigid model is applicable to the SEI formulated in tetraethylene glycol dimethyl ether(TEGDME)-based electrolyte.With the continuous formation of the SEI,its shear modulus decreases accompanied by an increase in viscosity.In TEGDME,the lightest/thinnest SEI(mass lower than in PC by a factor of nine) yet having the greatest stiffness(more than five times that in PC) is obtained.We attribute this behavior to differences in the chemical composition of the SEIs,which have been revealed by tracking the mass-change-per-mole-of-electrontransferred using EQCM-D and further confirmed by X-ray photoelectron spectroscopy.     

Protective layer with oligo(ethylene glycol) borate anion receptor for lithium metal electrode stabilization

The gel polymer electrolyte based on semi-IPN (interpenetrating polymer network) structure for the protection of lithium metal electrode was successfully developed by ultraviolet (UV) radiation-curing method. A curable mixed solution consists of linear polymer (Kynar 2801), crosslinking agent (1,6-hexanediol diacrylate), liquid electrolyte (ethylene carbonate (EC)/propylene carbonate (PC)/1 M LiClO₄), oligo(ethylene glycol) borate (OEGB) anion receptor, and photoinitiator (methyl benzoylformate). The OEGB was synthesized by the dehydrocoupling reaction of hydroxyl group in di(ethylene glycol) methyl ether with hydrogen in BH₃ and characterized by ¹H NMR. The presence of OEGB anion receptor in the protection layer could lead to an enhancement in the ionic conductivity, electrochemical stability, and the interfacial properties. The deposited lithium exhibited particle-like shape resulting from the introduction of the protection layer onto the lithium electrode surface. The unit cell based on the lithium anode protected with gel polymer electrolyte containing OEGB showed higher discharge capacity than that of the unit cell without OEGB after 100 cycles at C/2 rate (1.25 mA cm⁻²).     

二氟二草酸硼酸锂对LiFePO4/石墨电池高温性能的影响

研究了二氟二草酸硼酸锂(LiODFB)作为锂盐加入到碳酸丙烯酯(PC)+碳酸乙烯酯(EC)+碳酸甲乙酯(EMC)(质量比为1:1:3)混合溶剂中对LiFePO4/石墨电池高温(60 ℃)循环性能的影响. 用线性扫描伏安法(LSV)测试了电解液的电化学窗口. 通过等离子发射光谱(ICP)和能量散射光谱(EDS)对LiFePO4材料高温条件下在不同电解液中的稳定性进行了研究; 并用扫描电镜(SEM)和电化学交流阻抗谱(EIS)分析了石墨负极表面的固体电解液相界面(SEI)膜的热稳定性. 结果表明: 一方面LiODFB基电解液能抑制LiFePO4材料在高温条件下Fe(II)的溶解, 防止溶解的Fe(II)在石墨上还原, 有效地降低电池阻抗; 另一方面, 在LiODFB基电解液中形成的石墨负极表面SEI膜具有更好的热稳定性, 能显著提高LiFePO4/石墨电池的高温循环性能.     

P(VdF-HFP)-基离子液体复合聚合物电解质的阴极稳定性及热稳定性

以聚偏氟乙烯-六氟丙烯P(VdF-HFP)聚合物为基体, 制备了含离子液体1-甲基-3-乙基咪唑六氟磷酸盐(EMIPF6)、用于锂离子电池的离子液体复合聚合物电解质[P(VdF-HFP)/LiPF₆/EMIPF₆/EC(碳酸乙烯酯)-PC(碳酸丙烯酯)]. 采用热重分析法以及燃烧实验测试了复合聚合物电解质的热稳定性. 离子电导率测试表明, 离子液体的存在显著改善了复合聚合物电解质的离子传输; 循环伏安测试表明, 添加剂EC和PC的加入提高了复合电解质的阴极稳定性, 制得的离子液体复合聚合物电解质在0.3-4.3 V 电压范围内稳定存在. Li₄Ti₅O₁₂ 和LiCoO₂为电极材料、P(VdF-HFP)/LiPF₆/EMIPF₆/EC-PC 为电解质的半电池表现出优良的循环性能, 0.1C充放电倍率下, Li/LiCoO₂和Li/Li₄Ti₅O₁₂半电池的可逆容量分别为130和144 mAh·g^-1. 但EC、PC在一定程度上降低了离子液体复合聚合物电解质的热稳定性.     

纳米硅在含添加剂的高浓度电解液中循环特征及其表面协同成膜的研究

本文研究了在LiFSI-(PC)₃高浓度电解液中添加剂对于纳米硅材料的循环性能的影响,采用扫描电子显微镜、傅里叶变换红外光谱和X-射线光电子能谱分析了循环过程纳米硅材料及其电极的结构和表面SEI膜演化的特征. 结果表明,添加剂能够改善纳米硅材料的循环性能,在LiFSI-(PC)₃高浓度电解液中循环300周材料比容量为574.8 mAh·g^-1,而含有3%LiDFOB、3%FEC、3%TMSB的添加剂的高浓度电解液中,比容量分别为1142.9、1863.6和1852.2 mAh·g^-1. 作者分析认为,在LiFSI-(PC)₃浓溶液中LiFSI优先于PC在纳米硅表面发生成膜反应,形成的SEI膜由以无机物主导的内层膜和以有机物主导的外层膜组成,而在含添加剂的高浓度电解液中,添加剂和LiFSI协同参与SEI成膜反应,形成的内层膜能够减缓PC溶剂参与外层的成膜反应,由此形成的SEI膜能够抑制循环过程中SEI膜的过度生长,更好地抑制了纳米硅的粉化,纳米硅材料及其电极结构稳定性更好,材料表现出更好的循环性能.     

First-principles study of the effect of mechanical strength on ion transport in La-doped LiF-SEI on the Li (001) surface

The solid electrolyte interface (SEI) plays an important role in the lithium–sulfur battery system. It not only protects the stability of the lithium metal anode interface but also inhibits the growth of lithium dendrites during charge and discharge. The relationship between the shape of the SEI and the transport behavior of lithium ions affects the homogeneity of lithium dendrites. In this work, first-principles calculations are used to determine the stable structure and transport properties of the La-doped LiF solid electrolyte interface (La–LiF SEI) on the Li substrate. For the vertical transport of Li ions within the La–LiF SEI, the transport of Li ions in the grain boundary and that in the crystal grain was calculated separately. Regarding the plane diffusion behavior of Li ions between the La–LiF SEI and the lithium anode, the diffusion of Li ions on the surface and interface of the lithium anode were calculated. The effect of critical tensile strain on the diffusion of Li ions on the surface and interface was investigated. The results show that doping with La solves the problem of excessive periodic grain boundary gaps caused by the difference between LiF and Li lattices during the deposition process. The periodic gap is reduced from 0.478 nm to 0.306 nm after La doping. By comparing the migration energy barriers of each path, it is found that lithium ions are more likely to be inserted and extracted at the La–LiF SEI grain boundary. The reason is that the existence of the rare earth element La causes the grain boundary to have a more stable vacancy structure and a smaller transport energy barrier (0.789 eV). The critical tensile strain reduces the diffusion energy barrier (0.813 eV) of Li ions on the surface of the lithium metal anode, which promotes the fast diffusion and uniform deposition of Li ions between the interfaces. The establishment of SEI transport characteristics under the coupling conditions of mechanical stretching and ion transport is expected to improve the Li deposition behavior.     

Li-SGO掺杂半互穿网络型多孔单离子传导聚合物复合电解质的制备

本文成功制备了磺酸锂功能化石墨烯,通过原位聚合方式成功将其添加到单离子传导聚合物电解质中制备出磺酸锂功能化石墨烯改性半互穿网络型多孔单离子传导聚合物复合电解质.与未掺杂磺酸锂功能化石墨烯半互穿网络型多孔单离子传导聚合物电解质相比,该电解质具有更高的孔隙率、吸液率、机械拉伸强度和离子电导率.电化学测试结果表明,掺杂磺酸锂...     

新型锂盐LiBC2O4F2在EC＋DMC溶剂中的电化学行为

采用差热-热重(TG-DTA)、恒电流充放电和交流阻抗(EIS)分析了二氟草酸硼酸锂(LiODFB)的热稳定性,研究了LiODFB/碳酸乙烯酯(EC)+碳酸二甲酯(DMC)电解液的电化学性能及界而特征.实验结果表明,LiODFB不仅具有更高的热稳定性,而且在EC+DMC溶剂中具有较好的电化学性能.与使用LiPF6/EC+DMC的电解液相比,锂离子电池应用LiODFB基电解液在55℃的高温具有更好的容量保持能力;以0.5C、1C(1C=250 mA·g-1)倍率循环放电,两种电池间的倍率性能差别较小;LiODFB能够在1.5 V(vs Li/Li+)左右在石墨电极表面还原形成一个优异稳定的保护性固体电解质相界面膜(SEI膜);交流阻抗表明,使用LiODFB基电解液的锂离子电池仅具有稍微增加的界面阻抗.因此LiODFB是一种非常有希望替代LiPF6用作锂离子电池的新盐.     

Ordered and Fast Ion Transport of Quasi-solid-state Electrolyte with Regulated Coordination Strength for Lithium Metal Batteries

Polymer based quasi-solid-state electrolyte (QSE) has attracted great attention due to its assurance for high safety of rechargeable batteries including lithium metal batteries (LMB). However, it faces the issue of low ionic conductivity of electrolyte and solid-electrolyte-interface (SEI) layer between QSE and lithium anode. Herein, we firstly demonstrate that the ordered and fast transport of lithium ion (Li⁺) can be realized in QSE. Due to the higher coordination strength of Li⁺ on tertiary amine (−NR₃) group of polymer network than that on carbonyl (−C=O) group of ester solvent, Li⁺ can diffuse orderly and quickly on −NR₃ of polymer, significantly increasing the ionic conductivity of QSE to 3.69 mS cm⁻¹. Moreover, −NR₃ of polymer can induce in situ and uniform generation of Li₃N and LiN_xO_y in SEI. As a result, the Li||NCM811 batteries (50 μm Li foil) with this QSE show an excellent stability of 220 cycles at ≈1.5 mA cm⁻², 5 times to those with conventional QSE. LMBs with LiFePO₄ can stably run for ≈8300 h. This work demonstrates an attractive concept for improving ionic conductivity of QSE, and also provides an important step for developing advanced LMB with high cycle stability and safety.     

锂金属电池用三维半互穿网络聚合物电解质的制备

锂金属电池作为下一代高比能量电池技术受到人们越来越广泛的关注。然而由锂枝晶生长引发的安全问题是锂金属电池商业化面临的最大挑战之一。具有高锂离子迁移数和离子电导率的聚合物电解质是抑制锂枝晶生长的重要策略之一。本文将季戊四醇四丙烯酸酯和自由基引发剂AIBN添加至商业化电解液中,采用具有单离子传导功能的多孔聚合物电解质为锂金属电池的电解质隔膜,通过在电池内部发生热诱导原位聚合制备三维半互穿网络单离子传导聚合物电解质,达到提高电解质隔膜离子电导率和机械拉伸性能,以及有效抑制锂枝晶生长的目的。通过该策略的实施,成功获得了室温离子电导率0.53 mS·cm^-1和锂离子迁移数0.65的良好结果。应用于锂金属电池,证明该电解质能够有效抑制锂枝晶的生长和倍率性能的提高,为锂金属电池的开发提供了良好的解决路径。