Aterrei agora num estudo simpático:
"Study on Influencing Factors of Calendar Aging and Cycle Aging of LFP Batteries"
https://www.mdpi.com/2076-3417/15/23/12749
For calendar aging, capacity fade was strongly dependent on both SOC and temperature but only marginally influenced by preload. Higher calendar aging SOC accelerated degradation through intensified SEI growth, while OCV drift during long-term calendar aging revealed dynamic changes in anode potential that further shaped fade trends. Elevated temperature consistently accelerated capacity loss, reflecting the dominance of thermally enhanced side-reaction kinetics over polarization reduction. In contrast, pressure had little effect on either capacity fade or DCR increase, though resistance growth was found to be most pronounced at 50% SOC rather than at the highest SOC levels, indicating that impedance rise does not scale directly with SEI formation.
For cycle aging, degradation was primarily governed by charging rate, temperature, and SOC window, while preload exerted minimal influence. High-rate charging at 25 °C induced lithium plating and rapid capacity loss, whereas at elevated temperatures (45–60 °C), improved transport suppressed plating but accelerated SEI-driven fading. Discharge rate had a comparatively minor impact, with slower discharges producing more degradation due to longer time at temperature. Under low-rate cycling, preload did not affect capacity fade but amplified measured stress signals as aging progressed. The SOC window exerted a strong influence: wider ranges and higher maximum SOCs led to faster capacity fade and greater irreversible expansion, while narrower mid-range windows significantly mitigated both.
Overall, the results highlight that SOC management, temperature control, and charging protocols are critical levers for extending LFP battery lifetime, while preload primarily affects mechanical responses rather than electrochemical degradation.
Aqui está também o resultado que o EVUber referia de armazenamento (calendar aging): vale a pena armazenar a um SoC mais baixo e sem temperaturas elevadas.
E também o resultado do civic: ciclos mais pequenos (shallow) e a baixos SoC têm degradação menor.
E o que me farto de repetir:
as baterias LFP também degradam mais com carregamentos até aos 100% (ciclos em SoC mais elevados).
(
"Mas podes carregar as baterias LFP até aos 100% sem problema, ao contrário das NMC.")
Não, as baterias LFP não podem ser carregadas sempre até aos 100% sem problema.
Estudo interessante.
