Capacity Fade in Lithium-Ion Batteries and Cyclic Aging over Various State-of-Charge Ranges

Abstract

In order to develop long-lifespan batteries, it is of utmost importance to identify the relevant aging mechanisms and their relation to operating conditions. The capacity loss in a lithium-ion battery originates from (i) a loss of active electrode material and (ii) a loss of active lithium. The focus of this work is the capacity loss caused by lithium loss, which is irreversibly bound to the solid electrolyte interface (SEI) on the graphite surface. During operation, the particle surface suffers from dilation, which causes the SEI to break and then be rebuilt, continuously. The surface dilation is expected to correspond with the well-known graphite staging mechanism. Therefore, a high-power 2.6 Ah graphite/LiNiCoAlO2 cell (Sony US18650VTC5) is cycled at different, well-defined state-of-charge (SOC) ranges, covering the different graphite stages. An open circuit voltage model is applied to quantify the loss mechanisms (i) and (ii). The results show that the lithium loss is the dominant cause of capacity fade under the applied conditions. They experimentally prove the important influence of the graphite stages on the lifetime of a battery. Cycling the cell at SOCs slightly above graphite Stage II results in a high active lithium loss and hence in a high capacity fade.

Analytical Solution for Coupled Diffusion Induced Stress Model for Lithium-Ion Battery

“…The mechanical stress state within a spherical particle is completely described by the set of Equations (4)- (8). The elastic problem is solved for the displacement replacing the congruency equations (Equations (6) and 7) in the constitutive ones (Equations (4) and (5)), and the latter in the equilibrium equation (Equation 8).…”

“…Safety and batteries performance have been analysed through modelling and experimental tests in the last decades [4,5]. Progressive damage with charge/discharge cycles is the major weak point of lithium ion cells, since it affects the lifetime considerably [6]. The lithium ions are stored/withdrawn in the active material of the electrodes through insertion/extraction processes.…”

Determination of the Distribution of Relaxation Times by Means of Pulse Evaluation for Offline and Online Diagnosis of Lithium-Ion Batteries

“…Table 2 gives an overview about the deviating operating conditions for each scenario. The SOC range of each scenario was set in such a way that, according to [31], different degrees of capacity depletion and deterioration of the individual electrodes could be expected. The aging study thus enables an assessment of whether the sensitivity of the introduced method is sufficient to determine aging mechanisms qualitatively or even quantitatively.…”

An Improved Rainflow Algorithm Combined with Linear Criterion for the Accurate Li-ion Battery Residual Life Prediction

“…In contrast, there are few studies on the cycle life of Li-ion batteries. Besides, due to the strong nonlinear [25][26][27][28] characteristics of Li-ion batteries, there is little in-depth discussion on the effective cycle criteria of Li-ion batteries, and most studies use the criteria based on impedance and capacity [29][30][31][32]. As a result, the shortcomings of the cyclic method that it is difficult to accurately estimate the number of cycles has not been compensated.…”