Understanding Degradation at the Lithium-Ion Battery Cathode/Electrolyte Interface: Connecting Transition-Metal
Di Huang1,2, Chaiwat Engtrakul1, Sanjini Nanayakkara1
1National Renewable Energy Laboratory, Golden, Colorado 80401, United States.
ACS Applied Materials & Interfaces
|March 4, 2021
Summary
Investigating manganese dissolution from lithium-ion battery cathodes reveals that lithium salt anions significantly influence metal release and degradation product behavior, impacting battery performance.
Area of Science:
- Materials Science
- Electrochemistry
- Analytical Chemistry
Background:
- Lithium transition-metal oxides are key cathode materials in lithium-ion batteries, offering high capacity and energy density.
- Cathode/electrolyte interface degradation, particularly transition metal dissolution, limits battery lifespan and performance.
- Understanding metal dissolution mechanisms is crucial for developing more stable and durable battery technologies.
Purpose of the Study:
- To investigate the manganese dissolution process from a model lithium manganese oxide (LiMn2O4) cathode.
- To characterize the electrochemical properties of manganese degradation products.
- To elucidate the role of lithium salt anions in manganese dissolution and complex formation.
Main Methods:
- Utilized scanning electrochemical microscopy (SECM) to monitor manganese dissolution.
- Employed inductively coupled plasma (ICP) and electron paramagnetic resonance (EPR) spectroscopies for chemical analysis.
- Examined the electrochemical behavior of degradation products in electrolytes with varying lithium salt anions (ClO4-, PF6-, (CF3SO2)2N-).
Main Results:
- Successfully monitored manganese dissolution from a LiMn2O4 thin film cathode.
- Characterized the electrochemical behavior of dissolved manganese complexes.
- Observed a significant influence of lithium salt anions on the rate of manganese dissolution and the properties of resulting Mn complexes.
Conclusions:
- The identity of lithium salt anions in the electrolyte plays a critical role in the manganese dissolution mechanism from LiMn2O4 cathodes.
- Electrolyte composition, specifically the lithium salt anion, directly impacts cathode degradation pathways and battery performance.
- Findings suggest that careful selection of electrolyte components can mitigate transition metal dissolution and improve battery longevity.
Keywords:
LiMn2O4Mn dissolutioncathode/electrolyte interfacepolymer-assisted depositionscanning electrochemical microscopyMore Related Videos
Related Concept Videos
01:08Electrodeposition
926
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...
926
03:45Formation of Complex Ions
24.9K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
24.9K
04:02Weak Acid Solutions
40.8K
Few compounds act as strong acids. A far greater number of compounds behave as weak acids and only partially react with water, leaving a large majority of dissolved molecules in their original form and generating a relatively small amount of hydronium ions. Weak acids are commonly encountered in nature, being the substances partly responsible for the tangy taste of citrus fruits, the stinging sensation of insect bites, and the unpleasant smells associated with body odor. A familiar example of a...
40.8K
01:30Ladder Diagrams: Redox Equilibria
610
Ladder diagrams are useful tools for understanding redox equilibrium reactions, especially the effects of concentration changes on the electrochemical potential of the reaction. The vertical axis in the redox ladder diagrams represents the electrochemical potential, E. The area of predominance is demarcated using the Nernst equation.
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
610
00:56Extraction: Advanced Methods
774
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
774
02:21Electrolyte and Nonelectrolyte Solutions
68.6K
Substances that undergo either a physical or a chemical change in solution to yield ions that can conduct electricity are called electrolytes. If a substance yields ions in solution, that is, if the compound undergoes 100% dissociation, then the substance is a strong electrolyte. Complete dissociation is indicated by a single forward arrow. For example, water-soluble ionic compounds like sodium chloride dissociate into sodium cations and chloride anions in aqueous solution.
68.6K