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 Posted: Wed Sep 27, 2017 9:06 am    Post subject: Reaction heat of a LiNiMnCoO2 (NMC) Lithium-Ion Battery Hello, I'm trying to calculate the reversible reaction heat during charging and discharging of a Lithium-Ion Battery. Additionally Im trying to calculate the irreversible reaction heat of a battery that occurs as a result of high current. The positive active material of the Battery is LiNiMnCoO2 (NMC). The reaction equalation ist (M = Metal: Ni,Mn,Co): For the reversible heat during charging and discharging applies Q = dS * T. To calculate dS I need the Standard reaction enthalpy and the Gibbs free energy for Li Ni Mn Co O2. I would do it like in this pictue: Here is an other example for calculating the heat during charging and discharging of a Nickel-Metalhybrid (NiMH) battery: Result: dS * T for 25 °C Q1 = dS * T = 29,3 kJ/H2 mol They also calculated the irreversible heat, as a result of reaction of the electrolyt with the electrons occurs as a result of high current: Results: Standard reaction enthalpy dH = -285,9 kJ/mol And for the reversible heat T * dS = -48,6 kJ/mol (bei 25 °C) They also use this equalation, I'm not sure why: To calculate the reaction heat that occurs as result of high current, they used dH: Qreact = dH Gibbs free energy: dG = dH - dS * T. dS * T describes the Transformation of during charging and discharging emerging Energie in heat and dH the Transformation of the energy in mechanical work. I think this is the reason why they used dH. Chemistry is not my strongest skill, so i would be glad, if someone could help me. Kind regards Maxx
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