Reaction heat of a LiNiMnCoO2 (NMC) Lithium-Ion Battery
Posted: Wed Sep 27, 2017 9:06 am
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
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