在离子电解质中的离子佩尔蒂尔效应
Zhe Cheng1, Yu-Ju Huang1, Beniamin Zahiri1
1Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. d-cahill@illinois.edu.
Physical chemistry chemical physics : PCCP
|February 7, 2024
概括
研究人员开发了一种敏感的桥梁,用于测量离子电池中的微小温度差异. 这揭示了对热量和电荷传输的洞察力,这对于了解电化学材料和电池性能至关重要.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
背景情况:
- 合电荷和热传输为材料热力学和动力学提供了基本的见解.
- 了解这些运输现象对于开发先进的电化学设备至关重要.
研究的目的:
- 开发一种用于离子电化学电池中的离子佩尔蒂埃系数的敏感测量技术.
- 研究各种因素 (盐度,溶剂,电极材料,温度) 对离子传输的影响.
主要方法:
- 使用敏感的ac差电阻桥来准确测量温度差异 (比10μK更好).
- 在不同的实验条件下,在对称的离子电池中测量了离子佩尔蒂耶系数.
主要成果:
- 确定了负和大的离子佩尔蒂埃系数 (doi-Pdoi > 30 kJ mol-1).
- 观察到热流与离子漂移相反,在300K以上的温度下,系数增加.
- 佩尔蒂埃系数在扩散时间尺度上保持不变,表明热传输与变化相比起作用较小.
结论:
- 展示了一个新的平台来研究电化学细胞中的非平衡热力学.
- 通过温度和热电流测量,提供了对电化学材料传输特性的见解.
- 传统的电压和电荷电流测量用热传输数据来补充.
相关概念视频
P-N junction
534
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
534
Induced Electric Dipoles
4.2K
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
4.2K
Electrolysis
26.4K
In a galvanic cell, the electrical work is done by a redox system on its surroundings as electrons produced by the spontaneous redox reactions are transferred through an external circuit. Alternatively, an external circuit does work on a redox system by imposing a voltage sufficient to drive an otherwise nonspontaneous reaction in a process known as electrolysis. For instance, recharging a battery involves the use of an external power source to drive the spontaneous (discharge) cell reaction in...
26.4K
Dielectric Polarization in a Capacitor
4.7K
The presence of a dielectric medium in a capacitor not only changes the voltage and capacitance but also affects the electric field. In general, dielectrics can be of two types: polar and nonpolar. In a polar dielectric, the positive and negative charges in the molecules are separated by a distance and hence have a permanent dipole moment. In contrast, no such charge separation exists in a nonpolar dielectric, however the nonpolar molecules get polarized in the presence of an external electric...
4.7K
Batteries and Fuel Cells
27.4K
A battery is a galvanic cell that is used as a source of electrical power for specific applications. Modern batteries exist in a multitude of forms to accommodate various applications, from tiny button batteries such as those that power wristwatches to the very large batteries used to supply backup energy to municipal power grids. Some batteries are designed for single-use applications and cannot be recharged (primary cells), while others are based on conveniently reversible cell reactions that...
27.4K
Ionic Strength: Effects on Chemical Equilibria
1.5K
The addition of an inert ionic compound increases the solubility of a sparingly soluble salt. For example, adding potassium nitrate to a saturated solution of calcium sulfate significantly enhances the solubility of calcium sulfate. Le Châtelier's principle cannot predict this shift in the equilibrium. Instead, this could be explained in terms of changes in the effective concentration of the ions in solution in the presence of added inert salt.
In this solution, the primary...
In this solution, the primary...
1.5K


