Al掺杂对锰酸锂结构与性能的影响

采用固相法合成了Al掺杂的尖晶石LiAlxMn2-xO4(x=0～0.4).通过X射线衍射对LiAlxMn2-xO4的物相进行了研究,并探讨了Al掺杂对材料的充放电性能和电子电导率的影响.合成的LiAlxMn2-xO4均为纯尖晶石相.随着Al的掺入,LiAlxMn2-xO4的充放电循环性能得到改善,Al含量越高,循环过程中的容量衰减越小.电子电导率测试结果表明:掺杂Al后,降低了材料的电子电导率,这与Al的掺入降低了晶体中电子的离域作用有关.     

中热固相法制备掺杂钛的钒酸锂正极材料

以Li2CO3和V2O5为原料,用中热固相法制备了掺杂Ti4+的锂离子电池正极材料Li1.1V3―yTiyO8(y=0.05、0.1、0.2),并对其电化学性能进行了研究。研究表明,掺杂Ti能够很好地改善中热固相法产品的电化学性能,且当y=0.1时,Li1.1V3―yTiyO8循环性能最好,首次放电比容量高达250.9 mAh/g。     

有关IATA DGR50版与49版锂电池航空运输包装指引的差异说明

详细介绍了IATA DGR 50版与49版关于锂电池包装指引的差异。     

如何延长UPS中免维护蓄电池组的使用寿命

UPS电源其后备储能设备采用免维护蓄电池组,免维护蓄电池组维护的好坏对电源的寿命和故障率有很大影响,文中根据使用中的具体情况和维护经验介绍UPS中免维护蓄电池组的使用注意事项和日常维护要求,以延长免维护蓄电池组的使用寿命。     

锂离子电池正极材料LiFePO_4的研究进展

橄榄石型LiFePO4正极材料具有原料来源丰富、无毒、环境友好、理论容量较高、热稳定性和循环性能好等特点,是近年来迅速发展起来的一种锂离子电池的正极材料。综述了新型锂离子电池正极材料LiFePO4的研究进展,重点阐述了LiFePO4材料的结构、制备方法、改性研究,并对发展方向进行了展望。     

锂离子动力电池用气凝胶隔热材料研究进展

近年来,新能源汽车行业发展迅猛。锂离子电池因其能量密度大、循环寿命长等优势成为应用最广泛的动力电池,但其在极端条件下存在热失控安全问题。气凝胶作为一种新型纳米多孔隔热材料,复合材料耐温可达1000℃以上,其凭借优异的隔热性能及轻质、防火、环保等特性,被逐渐应用于新能源汽车电池电芯隔热防火。本文介绍了锂离子电池热失控现象及热防护措施,常用的气凝胶隔热材料及其应用于锂电池中的性能优势,并与传统动力电池隔热材料进行对比,最后对其应用前景进行展望。     

Stabilizing Polymer–Lithium Interface in a Rechargeable Solid Battery

Solid polymer electrolytes (SPEs) are promising candidates for developing high‐energy‐density Li metal batteries due to their flexible processability. However, the low mechanical strength as well as the inferior interfacial regulation of ions between SPEs and Li metal anode limit the suppress ion of Li dendrites and destabilize the Li anode. To meet these challenges, interfacial engineering aiming to homogenize the distribution of Li⁺/electron accompanied with enhanced mechanical strength by Mg₃N₂ layer decorating polyethylene oxide is demonstrated. The intermediary Mg₃N₂ in situ transforms to a mixed ion/electron conducting interlayer consisting of a fast ionic conductor Li₃N and a benign electronic conductor Mg metal, which can buffer the Li⁺ concentration gradient and level the nonuniform electric current distribution during cycling, as demonstrated by a COMSOL Multiphysics simulation. These characteristics endow the solid full cell with a dendrite‐free Li anode and enhanced cycling stability and kinetics. The innovative interface design will accelerate the commercial application of high‐energy‐density solid batteries.     

Constructing Na‐Ion Cathodes via Alkali‐Site Substitution

Na‐ion batteries have experienced rapid development over the past decade and received significant attention from the academic and industrial communities. Although a large amount of effort has been made on material innovations, accessible design strategies on peculiar structural chemistry remain elusive. An approach to in situ construction of new Na‐based cathode materials by substitution in alkali sites is proposed to realize long‐term cycling stability and high‐energy density in low‐cost Na‐ion cathodes. A new compound, [K_0.444(1)Na_1.414(1)][Mn_3/4Fe_5/4](CN)₆, is obtained through a rational control of K⁺ content from electrochemical reaction. Results demonstrate that the remaining K⁺ (≈0.444 mol per unit) in the host matrix can stabilize the intrinsic K‐based structure during reversible Na⁺ extraction/insertion process without the structural evolution to the Na‐based structure after cycles. Thereby, the as‐prepared cathode shows the remarkably enhanced structural stability with the capacity retention of >78% after 1800 cycles, and a higher average operation voltage of ≈3.65 V versus Na⁺/Na, directly contrasting the non‐alkali‐site‐substitution cathode materials. This provides new insights into alkali‐site‐substitution constructing advanced Na‐ion cathode materials.     

Engineering of Polyanion Type Cathode Materials for Sodium‐Ion Batteries: Toward Higher Energy/Power Density

The development of high energy/power density sodium‐ion batteries (SIBs) is still challenged by the high redox potential of Na/Na⁺ and large radius of Na⁺ ions, thus requiring extensive further improvement to, in particular, enhance the capacity and voltage of cathode materials. Among the various types of cathodes, the polyanion cathodes have emerged as the most pragmatic option due to their outstanding thermostability, unique inductive effect, and flexible structures. In this Review, a critical overview of the design principles and engineering strategies of polyanion cathodes that could have a pivotal role in developing high energy/power density SIBs are presented. Specifically, the engineering of polyanion cathode materials for higher voltage and specific capacity to increase energy density is discussed. The way in which morphology control, architectural design, and electrode processing have been developed to increase power density for SIBs is also analyzed. Finally, the remaining challenges and the future research direction of this field are presented.     

High‐Power Lithium Metal Batteries Enabled by High‐Concentration Acetonitrile‐Based Electrolytes with Vinylene Carbonate Additive

To enable next‐generation high‐power, high‐energy‐density lithium (Li) metal batteries (LMBs), an electrolyte possessing both high Li Coulombic efficiency (CE) at a high rate and good anodic stability on cathodes is critical. Acetonitrile (AN) is a well‐known organic solvent for high anodic stability and high ionic conductivity, yet its application in LMBs is limited due to its poor compatibility with Li metal anodes even at high salt concentration conditions. Here, a highly concentrated AN‐based electrolyte is developed with a vinylene carbonate (VC) additive to suppress Li⁺ depletion at high current densities. Addition of VC to the AN‐based electrolyte leads to the formation of a polycarbonate‐based solid electrolyte interphase, which minimizes Li corrosion and leads to a very high Li CE of up to 99.2% at a current density of 0.2 mA cm^‐2. Using such an electrolyte, fast charging of Li||NMC333 cells is realized at a high current density of 3.6 mA cm^‐2, and stable cycling of Li||NMC622 cells with a high cathode loading of 4 mAh cm^‐2 is also demonstrated.