在非水性Li-O2细胞中的碳电极
Muhammed M Ottakam Thotiyl1, Stefan A Freunberger, Zhangquan Peng
1School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, United Kingdom.
Journal of the American Chemical Society
|November 30, 2012
概括
氧电池中的碳阴极在3.5V以上是不稳定的,分解成碳酸并促进电解质分解. 疏水性碳具有更好的稳定性,但电解质相互作用仍然是实际应用的挑战.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 储能 储能 储能 储能 储能 储能
背景情况:
- 碳材料被广泛用于非水性氧 (Li-O(2) 细胞中的多孔阴极.
- 碳阴极的稳定性及其对电解质分解的影响对电池性能至关重要.
- 碳表面特性 (疏水性/疏水性) 影响细胞行为.
研究的目的:
- 在循环过程中研究Li-O(2) 细胞中碳阴极的稳定性.
- 了解碳和电解质分解的机制.
- 为了评估碳表面特性在细胞性能中的作用.
主要方法:
- 在Li-O(2) 电池中循环2~4V的碳阴极的分析.
- 使用酸处理和芬顿试剂进行表面分析.
- 微分电化学质谱法 (DEMS) 和富里埃变换红外光谱法 (FTIR).
主要成果:
- 碳阴极在3.5V以下是稳定的,但在3.5V以上充电时会分解为Li(2) CO(3).
- 碳促进电解质分解,形成Li(2) CO(3) 和Li碳酸盐,导致极化.
- 水友性碳是不那么稳定,并且在分解电解质方面比疏水性碳更具有催化活性.
结论:
- 在Li-O(2) 细胞中的碳阴极稳定性受到3.5V以上的氧化分解和电解质相互作用的限制.
- 二氧化碳和二氧化碳酸盐的积累导致容量色和电极被动化.
- 有效的-O(2) 电池循环需要考虑电极和电解质稳定性的协同方法.
相关概念视频
Batteries and Fuel Cells
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...
Voltaic/Galvanic Cells
Spontaneous Chemical Reactions
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
Electrochemical Cells
Electrochemical cells are systems that convert chemical energy into electrical energy or use electrical energy to drive chemical reactions. They consist of two electrodes in contact with an electrolyte, where redox reactions enable electron transfer. Most electrochemical cells include two half-cells connected by an external wire for electron flow and a salt bridge for ion flow. The salt bridge contains an electrolyte solution and maintains charge neutrality by allowing ions—not electrons—to...
Types of Reversible Electrodes
For electrode reversibility to be maintained, all the reactants and products involved in the half-reaction must be present at the electrode. There are several types of reversible electrodes (half-cells).In metal-metal-ion electrodes, a metal balances electrochemically with a solution of its own ions. Examples are Cu2+|Cu and Zn2+|Zn. Metals that react with the solvent, like group 1 and most group 2 metals, which react with water, and zinc, which reacts with aqueous acidic solutions, cannot be...
Electrodes: Overview
Electrochemical measurements are conducted in an electrochemical cell composed of various components that control and measure the current and potential. One fundamental component is electrodes, conductive materials that enable electron transfer reactions at their surfaces.
There are two main types of electrodes in electrochemical cells. The first type, known as the working or indicator electrode, has a potential that is sensitive to the analyte's concentration and reacts to changes in the...
There are two main types of electrodes in electrochemical cells. The first type, known as the working or indicator electrode, has a potential that is sensitive to the analyte's concentration and reacts to changes in the...
Electrodeposition
Electrodeposition is a technique used to separate an analyte from interferents by electrochemical processes. Here, the analyte is a metal ion that can be deposited on an electrode immersed in the sample solution. The electrochemical setup consists of an anode and a cathode. When an electric current is applied to the setup, oxidation occurs at the anode. At the cathode, which consists of a large metal surface, metal ions undergo reduction and deposit onto the surface.
Electrodeposition can...
Electrodeposition can...


