New Use of LiMn2O4 Batteries Under Renewable Overvoltage as Thermal Power Generators: Energy and Exergy Analysis

Lithium-ion batteries are extensively used for energy storage in renewable, electronic, and automotive applications. However, once their electrical capacity is exhausted, they become AcademicEditor: Grigorios L. Kyriakopoulos Received: 23September2025 Revised: 20October2025 Accepted: 21October2025 P...

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Detalles Bibliográficos
Autores: Ríos Fernández, Juan Carlos|||0000-0002-2984-9206, Álvarez Fernández, Martina Inmaculada|||0000-0002-5681-6530
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universidad de Oviedo (UNIOVI)
Repositorio:RUO. Repositorio Institucional de la Universidad de Oviedo
Idioma:inglés
OAI Identifier:oai:digibuo.uniovi.es:10651/80790
Acceso en línea:https://hdl.handle.net/10651/80790
https://dx.doi.org/10.3390/su17219438
Access Level:acceso abierto
Palabra clave:Energy and exergy analysis
Lithium-ion batteries
MnO2 cathode
SDG 12
Descripción
Sumario:Lithium-ion batteries are extensively used for energy storage in renewable, electronic, and automotive applications. However, once their electrical capacity is exhausted, they become AcademicEditor: Grigorios L. Kyriakopoulos Received: 23September2025 Revised: 20October2025 Accepted: 21October2025 Published: 23 October2025 Citation: Ríos-Fernández, J.C.; Álvarez Fernández,M.I.NewUseof LiMn2O4 BatteriesUnderRenewable Overvoltage asThermalPower Generators: EnergyandExergy Analysis. Sustainability 2025, 17, 9438. https://doi.org/10.3390/ su17219438 Copyright: ©2025bytheauthors. Licensee MDPI,Basel,Switzerland. This article is an open access article distributed under the termsand conditions of the Creative Commons Attribution (CC BY)license (https://creativecommons.org/ licenses/by/4.0/). hazardous waste that requires energy-intensive recycling processes. This study investigates the thermodynamic and exergetic behavior of LiMn2O4-based lithium-ion batteries subjected to controlled electrical overvoltage from renewable energy sources, aiming to quantify their potential for thermal energy generation and recovery. A detailed mathematical model was developed to describe the coupled heat transfer and electrochemical phenomena occurring during overvoltage conditions, and experimental validation was performed under various voltage levels and charging states. Energy and exergy analyses were applied to determine the configuration yielding the highest conversion efficiency for both new and aged cells. The maximum thermal energy efficiency reached 81% for new batteries and 4% for used batteries, while the corresponding exergetic efficiencies were 5% and 1.6%, respectively. Although this study does not propose the immediate large-scale reuse of spent batteries as thermal devices, the results provide quantitative insight into irreversible energy conversion processes and highlight their potential contribution to waste heat recovery and energy optimization strategies in sustainable industrial systems. This thermodynamic framework offers a novel approach for valorizing end-of-life batteries within circular energy models, reducing environmental impact, and advancing the integration of renewable energy-driven heat recovery technologies.