Study and modeling of the functioning and aging of Lithium-ion Capacitors (LiC)
Description
Lithium-Ion Capacitors (LiCs) are the new emerging technology of hybrid supercapacitors that combines the advantages of conventional supercapacitors and lithium-ion batteries. They provide intermediate energy and power densities due to their hybrid composition based on a positive electrode made of activated carbon similar to that of supercapacitors and a negative electrode made of pre-lithiated carbon similar to that of lithium-ion batteries. The aim of this thesis is to study the aging of commercial LiCs using two accelerated aging procedures: calendar aging and cycle aging. One of their main particularities concerns the nonlinear capacitance evolution with respect to their voltage (C(V) curve). The first accelerated aging test is related to the calendar life of LiCs that represents their behavior independently of their usage. The degradation of their parameters due to aging is mainly affected by the voltage and the temperature only. These tests were applied to several cells at three different voltage values and two temperatures. The evolution of their impedances were followed during the whole aging period in order to identify an electrical model that can accurately describe the progress of aging and that possesses electrochemically meaningful parameters. The best voltage value that ensures the extension of the lifetime of LiCs was identified using the results of these tests. In addition, aging mechanisms that extremely depend on the applied voltage value were identified. They highlight the particularity of the functioning of LiCs. These results were confirmed using post-mortem analyses. The second accelerated aging test is the cycle aging that assesses the impact of the current on the life cycle of LiCs. The choice of current profiles was based on the electrochemical operating principle of LiCs. The evolution of the impedances and the C(V) curves of LiCs were compared and analyzed. Aging mechanisms produced during cycle aging were also evaluated. They depend on the voltage range in which the LiC operates. The optimal voltage window that guarantees a long lifetime of LiCs was highlighted. (author)
Abstract (French)
Le 'Lithium-Ion Capacitor' (LiC) est un supercondensateur hybride dont les caracteristiques peuvent etre placees entre un condensateur a double couche electrique (supercondensateur) et une batterie lithium-ion. Il possede des densites d'energie et de puissance intermediaires grace a sa composition hybride a base d'une electrode positive en charbon actif identique a celle d'un supercondensateur et d'une electrode negative en carbone pre-lithie identique a celle d'une batterie lithium-ion. L'objectif de cette these est d'etudier le vieillissement des LiC industrialises aussi bien dans le cadre d'un vieillissement en stockage (calendaire) qu'en utilisation (cyclage). Un de leur specificite principale concerne l'evolution particuliere de leur capacite en fonction de la tension a leurs bornes (C(V)). Le premier type de vieillissement qu'est le vieillissement calendaire permet de representer le comportement des LiC lorsqu'ils sont stocker avant utilisation ou lorsqu'ils sont en veille. La degradation de leurs parametres liee au vieillissement, est alors essentiellement influencee par leur tension et la temperature. Des essais de vieillissement a trois tensions caracteristiques et deux temperatures differentes sont etudies. L'evolution des impedances des cellules a ete suivie tout au long du vieillissement afin d'identifier un modele electrique de suivi du vieillissement dont les parametres sont lies aux phenomenes electrochimiques. Par ces essais, la meilleure tension de stockage des LiC, permettant la prolongation de leur duree de vie a ete mise en evidence. Par ailleurs, des mecanismes de vieillissement differents d'une tension caracteristique a l'autre sont reveles et soulignent la specificite de fonctionnement des LiC. Ces resultats ont ete confirmes par des analyses post-mortem. Le second type de vieillissement etudie est le vieillissement par cyclage qui prend en compte l'impact du courant sur la duree de vie des LiC. Le choix des profils de courant de cyclage a ete effectue en considerant le principe de fonctionnement electrochimique des LiC. Les evolutions des impedances et des courbes C(V) des cellules sont comparees et interpretees. Les mecanismes de vieillissement prenant naissance lors du cyclage continu sont abordes. Ils dependent de la fenetre de potentiel sur laquelle les LiC fonctionnent pendant leur utilisation. La fenetre de tension optimale qui assure une longue duree de vie des LiC est aussi mise en evidence. (auteur)
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Additional details
Additional titles
- Original title (French)
- Etude et modelisation du fonctionnement et du vieillissement des 'Lithium-Ion Capacitors' (LiC)
Publishing Information
- Imprint Pagination
- 158 p.
- Report number
- FRNC-TH--12018
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 52097850
- Subject category
- S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- AGING; CAPACITIVE ENERGY STORAGE EQUIPMENT; CAPACITY; ELECTRIC CONDUCTIVITY; ELECTRIC IMPEDANCE; ELECTRIC POTENTIAL; ENERGY DENSITY; FREQUENCY DEPENDENCE; LIFETIME EXTENSION; LITHIUM ION BATTERIES; NYQUIST DIAGRAMS; TEMPERATURE DEPENDENCE
- Descriptors DEC
- DIAGRAMS; ELECTRIC BATTERIES; ELECTRICAL PROPERTIES; ELECTROCHEMICAL CELLS; ENERGY STORAGE SYSTEMS; ENERGY SYSTEMS; EQUIPMENT; IMPEDANCE; INFORMATION; LIFETIME; PHYSICAL PROPERTIES; SERVICE LIFE
Optional Information
- Notes
- 154 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses