Work

Performance degradation and failure characterization of Li-ion batteries in hearing aids: Insights from field data

Year: 2025

Type: article

Abstract: Lithium-ion batteries (LIBs) are widely used due to their high energy density, power density, and low self-discharge rates, powering applications from portable electronics to electric vehicles. However, despite technological advances, LIBs face challenges in reliability and performance, particularly if used in devices exposed to climatical stress. Devices like hearing aids (HAs), which benefit from miniaturization and LIB technology, are vulnerable to electronic corrosion due to their exposure to harsh conditions, which could influence LIBs charging and discharge characteristics if power management circuits malfunction. This has led to critical reliability issues on electronic devices and LIBs used in hearing aids. This research investigates LIB failure modes in field failed batteries used in hearing aids through electrochemical techniques and imaging methods. Cyclic testing was utilized to replicate failures by stressing new batteries to study the effects of electronic corrosion. The results showed that a high discharge current and deep depth of discharge, due to exposure conditions, can accelerate the battery degradation, leading to increased capacity and power fade. The field-failed batteries showed reduced discharge capacity and reduced electrochemical performance due to the increased internal resistance (fx. microcrack formation on electrodes, loss of lithium inventory) and an increased barrier to electron transfer (fx. SEI layer growth) and slower electron transfer reactions. The findings highlight the risk of electronic corrosion on components in power management circuits, which can compromise the reliability of LIBs in hearing aids. • Corrosion on the HA's PCBA led to accelerated degradation in the Li-ion batteries. • The field failed batteries showed increased internal resistance measured by EIS. • CV curves indicated an increased barrier to electron transfer in failed batteries. • Battery cyclic tester was utilized to recreate the field failures on new batteries. • High discharge currents and deep depth of discharge led to increased capacity fade.

Source: Journal of Power Sources

DOI: 10.1016/j.jpowsour.2025.236764

Authors: Markus Asikainen, Feng Li, Kapil Kumar Gupta, Abhijeet Yadav, Rajan Ambat

Institution: Technical University of Denmark

Language: English

Topic: Advanced Battery Technologies Research

Subfield: Automotive Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,230