不对称的提取和插入高压线圈中的快速速率
Muhammad Mominur Rahman1, Kangxuan Xia1, Xiao-Qing Yang1
1Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States.
Nano letters
|July 18, 2023
概括
订购-LiNi0.5Mn1.5O4 (o-LNMO) 在离子电池中显示了取决于速率的相位过渡. 快速充电涉及粒子对粒子的反应,而快速放电则表现出核心外机制.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 固态化学 固态化学
背景情况:
- 螺旋结构订购-LiNi0.5Mn1.5O4 (o-LNMO) 是离子电池的有前途的阴极材料,可以替代含有的化合物.
- 在缓慢的充电/放电速度下,o-LNMO表现出两种截然不同的两相反应.
研究的目的:
- 为了研究o-LNMO的取决于速率的相位过渡行为.
- 为了确定在缓慢的速度下观察到的两相反应是否在快速的充电/放电速度下持续存在.
主要方法:
- 使用*在操作*时间解析的X射线衍射来监测电化学循环期间的相变.
- 在不同的充电和放电率下分析了o-LNMO的结构演变.
主要成果:
- 对于不同速率的充电和放电过程,确定了一个狭窄的固体溶液反应区域.
- 在快速速度下,相位过渡机制高度不对称.
- 由于异步反应,快速充电通过粒子对粒子机制进行.
- 快速放电可能涉及核心外机制,在外层颗粒层中插入Li+.
结论:
- o-LNMO的相位过渡行为取决于速率,并表现出不对称性.
- 在快速放电期间,Li0.5Ni0.5Mn1.5O4相被抑制,并在放松后出现.
- 了解这些机制对于优化高功率离子电池的o-LNMO性能至关重要.
相关概念视频
Reducing Line Loss
In a three-phase circuit, line loss is an indicator of energy dissipated as heat due to the resistance of transmission lines. To address this, incorporating transformers into the system—a step-up transformer at the source and a step-down transformer at the load—is a strategic solution. Two three-phase transformers are introduced to improve this.
With a step-up transformer at the source, the voltage is increased, thereby reducing the current in the transmission lines since power loss in...
With a step-up transformer at the source, the voltage is increased, thereby reducing the current in the transmission lines since power loss in...
Fast Reactions
Fast reactions occurring in times shorter than the time needed to mix reactants pose a unique challenge for investigation. In a liquid-phase continuous-flow system, reactants A and B are swiftly pushed into the mixing chamber, where mixing occurs within 1 ms. The reaction mixture then flows through an observation tube, and one measures light absorption to determine species concentrations at various points of the tube. This method is most appropriate when relatively large volumes of reactants...
Lossless Lines
In electrical engineering, a lossless transmission line is characterized by a purely imaginary propagation constant and a resistive characteristic impedance. The ABCD parameters, which describe the relationship between the input and output voltages and currents, indicate an equivalent π circuit with an imaginary series impedance and a shunt admittance. This results in a transmission line that, when the product of the phase constant (beta) and the length of the line is less than pi, exhibits...
Fast Decoupled and DC Powerflow
The fast decoupled power flow method addresses contingencies in power system operations, such as generator outages or transmission line failures. This method provides quick power flow solutions, essential for real-time system adjustments. Fast decoupled power flow algorithms simplify the Jacobian matrix by neglecting certain elements, leading to two sets of decoupled equations:
Three-Phase Short Circuit—Unloaded Synchronous Machine
Conducting a three-phase short circuit test on an unloaded synchronous machine helps understand its impact on the system. The AC fault current's oscillogram, with the DC offset removed, reveals that the waveform amplitude decreases from an initially high value to a steady-state level for one phase of the machine.
This behavior occurs due to the magnetic flux produced by the short-circuit armature currents. Initially, these currents follow high-reluctance paths but eventually shift to...
This behavior occurs due to the magnetic flux produced by the short-circuit armature currents. Initially, these currents follow high-reluctance paths but eventually shift to...
Lossy Lines and Overvoltages
Transmission-line series resistance and shunt conductance cause three primary effects: attenuation, distortion, and power losses.
Attenuation
When constant series resistance and shunt conductance are present, voltage and current equations are modified. The propagation constant indicates that voltage and current waves consist of both forward and backward traveling components. These waves attenuate as they propagate, with the attenuation factor related to the resistance and conductance. In a...
Attenuation
When constant series resistance and shunt conductance are present, voltage and current equations are modified. The propagation constant indicates that voltage and current waves consist of both forward and backward traveling components. These waves attenuate as they propagate, with the attenuation factor related to the resistance and conductance. In a...


