Role of negative electrode porosity in long-term aging of NMC//Graphite Li-Ion batteries

P. Bernard (1, 2, 3) , Hervé Martinez (2) , C. Tessier (4, 5) , E. Garitte (4, 5) , S. Franger (3) , Rémi Dedryvère (6, 2, 4)

1 IPGP - Institut de Physique du Globe de Paris
2 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
3 ICMMO - Institut de Chimie Moléculaire et des Matériaux d'Orsay
4 RS2E - Réseau sur le stockage électrochimique de l'énergie
5 SAFT [Bordeaux]
6 ALISTORE-ERI - Advanced Lithium Energy Storage Systems - ALISTORE-ERI

Electrochemical energy storage associated to renewable energy sources requires devices with very long lifespan. In this work we simulated the long-term aging of Li(Ni2/5Mn2/5Co1/5)O2 (NMC)//graphite lithium-ion batteries by standardized accelerated aging tests in tough storage and cycling conditions. Aging mechanisms taking place at the graphite electrode/electrolyte interface were characterized by X-ray Photoelectron Spectroscopy (XPS) and Electrochemical Impedance Spectroscopy (EIS). Besides usual aging processes commonly admitted, we highlight the role of electrode porosity. A model is proposed to describe the electrical behavior of the electrodes taking into account the influence of electrochemically blocking pores. The blocking effect of pores is believed to be caused by confinement of Li2CO3 and/or gaseous CO2 inside the narrow pores, which do not allow lithium ions to diffuse and insert into graphite. In these pores, lithium can only participate to SEI growth which decreases the capacity by lithium consumption. © 2015 The Electrochemical Society.

Mots clés: Accelerated aging test; Carbon dioxide; Cycling conditions; Electrical behaviors; Electric batteries; Electrochemical electrodes; Electrochemical energy storage; Electrochemical impedance spectroscopy; Electrode/electrolyte interfaces; Electrode porosity; Electrodes; Graphite; Graphite electrodes; Ions; Lithium; Lithium alloys; Lithium compounds; Lithium-ion batteries; manganese; Negative electrode; Porosity; Renewable energy resources; Renewable energy source; Secondary batteries; Testing; X ray photoelectron spectroscopy

Domaines: Chimie; Matériaux

P. Bernard, Hervé Martinez, C. Tessier, E. Garitte, S. Franger, et al.. Role of negative electrode porosity in long-term aging of NMC//Graphite Li-Ion batteries. Journal of The Electrochemical Society, 2015, 162 (13), pp.A7096--A7103. ⟨10.1149/2.0151513jes⟩. ⟨hal-01498386⟩