Study on the Capacity Degradation Mechanism and Capacity Predication of Lithium-Ion Battery Under Different Vibration Conditions in Six Degrees-of-Freedom

Abstract

In order to study the degradation mechanism of Lithium-ion batteries subjected to vibration aging in actual use and also to achieve capacity estimation and prediction, the following work has been done: First, the road spectra of two commonly seen domestic roads in China are collected in the field and modeled on a six-degree-of-freedom motion platform as the vibration working conditions of the batteries. Secondly, aging cycle experiments were conducted on batteries with different placement directions (X-axis direction, Y-axis direction, and Z-axis direction) under two vibration conditions, and the effects of experimental conditions on the decline results were analyzed. Thirdly, quantification of battery decline patterns to analyze the main causes of battery capacity decline. Then, through further analysis of the two vibration conditions on the lithium battery by in-situ and ex-situ methods as its internal mechanisms. Finally, the quantified results were input into the GAN-LSTM prediction model to predict the capacity, and the errors of 20 predictions are: The average values are 2.8561% for group X, 2.7997% for group Y, 3.0182% for group Z, and 2.9478% for group N, which meet the requirements of battery management system estimation. This paper provides a basis for the study of aging mechanism and capacity estimation of lithium-ion batteries under vibration aging conditions, which helps manufacturers to package batteries more rationally to extend battery life and develop BMS-related strategies.

Direct measurement of internal temperatures of commercially-available 18650 lithium-ion batteries

“…One possible reason is the insertion process likely causes slight physical damage to both the cathode and anode materials, which could also lead to some removal of those materials from the electrodes. Studies have shown that mechanical agitation of cells, such as vibration 11 , 12 , dynamic impact 13 , 14 , and partial nail puncture 15 , 16 , can cause an accelerated loss of discharge capacity beyond what is normally seen during typical cycling. This same effect could be occurring to the cells under test, since the electrodes experience some physical agitation during widening of the center of the windings for RTD insertion.…”

Analysis of Capacity Decay, Impedance, and Heat Generation of Lithium-ion Batteries Experiencing Multiple Simultaneous Abuse Conditions

“…However, the dynamic load was only applied for a short time before operation according to the UN 38.3 standard, and no vibration was applied during the cycling of the cells. Li et al [6] analyzed the degradation of capacity in cells subjected to vibration in six degrees of freedom to simulate operation in a UAV, but did not incorporate any other physical abuse. Savoye et al [7] investigated how periodic pulses are detrimental to cell operation compared to cells cycled with constant currents, but did not combine these electrochemical stresses with any physical abuse.…”