Online Detection of Soft Internal Short Circuit in Lithium-Ion Batteries at Various Standard Charging Ranges

Abstract

Soft internal short circuit (ISCr) in lithium-ion batteries is a latent risk, and it is a primary reason for thermal runaway with blaze and explosion. Early detection of ISCr is necessary to ensure safe utilization of the batteries. Based on the applications of batteries, load currents are considerably diverse and occasionally do not satisfy the persistent excitation condition, resulting in inaccurate detection of soft ISCr with existing model-based methods. Using constant current for standard charging of the batteries, this study proposes a novel and accurate model-based algorithm to detect soft ISCr online irrespective of the specific type of load currents. An equivalent circuit model of the battery with ISCr is used to extract open circuit voltage of the battery. Enhanced relationship between open circuit voltage and state of charge is obtained to estimate ISCr resistance as a fault index. To improve estimation accuracy of the fault index, factors affecting the ISCr resistance are analyzed and considered. Experiments incorporating various charging ranges and soft ISCr conditions below 100 are configured, and the proposed method is verified with experimental data. The results of the study indicate that the relative error of the estimated fault index does not exceed 6.4%; thereby, the battery management system is enabled to accurately detect an ISCr early.

Artificial Interphase Layer for Stabilized Zn Anodes: Progress and Prospects

“…[187] In terms of galvanostatic cycling performance for symmetric cells, many reported cycling lifespan might not be reliable because of the possible occurrence of soft short-circuits. [188,189] Moreover, in situ optical microscopy is widely applied to reveal dynamic variation of deposition landscape. Nevertheless, separator is often excluded from the observation equipment, which deviates from the real situation in operational batteries since dendrite issues may be aggravated with the presence of separators.…”

Isolation of relaxation times under open-circuit conditions: Toward prognosis of nascent short circuits in Li-ion batteries

“…According to one industry standard (GB/T 31484-2015), the maximum leakage current allowed in a battery system to be classified as a soft short is C/3.7 (where C is the 1C current). 9 , 15 , 16 This translates to a short resistance, R sh , of approximately 3Ω–6Ω for typical commercial mobile phone batteries (example: for a 4Ah battery with nominal voltage ∼3.85V, R sh = [3.85V/(4A/3.7)] ∼ 3Ω), with this number varying, depending on the battery capacity/form factor. An easier way to differentiate the soft-hard transition is the short resistance below which the signatures become noticeable.…”

Fault Identification of Lithium-Ion Battery Pack for Electric Vehicle Based on GA Optimized ELM Neural Network

“…Compared with other batteries, lithium-ion power battery has been widely used in the electric vehicle industry due to the advantages of wide working temperature range, high energy density, high power density, and low self-discharge rate [6]. However, many electric vehicle fire incidents have been caused mainly by battery failure [7][8][9]. The batteries themselves are a highly complex system with interdependent features.…”