modeling of ageing of li-ion battery at low temperatures
DESCRIPTION
Background The use of batteries in vehicles is increasing very strongly today. Still there remains a substantial amount of work regarding the ageing modelling of batteries. One specific ageing factor is operation at low temperatures, especially charging. The ageing processes lead to a drastically increased internal resistance, reduced power capability and capacity decrease. In this thesis, an equivalent circuit based ageing model will be implemented with focus on single Li-ion cells for resistance increase and capacitance decrease and the obtained values of the circuit components will be related to the electrochemical processes in the cells. The chosen Li-ion chemistry in this work is LiFePO4. Approximately 10 cells will be tested under realistic, but accelerating operating conditions. The specific ageing factor which is of interest in this work is charging at low temperature (-15°C …0°C).TRANSCRIPT
Avnish Narula ö
ö
1
2
…
3
4
… …
° °
5
…
–
7
6
7
… …
8
°
9
11
10
®
11
12
…
°
°
°
°
°
°
°
°
°
°
13
… …
)()(),( , TVSoCVTSoCV ocrefococ
14
…
SoC
a
SoCa
oc eaSoCaaeaSoCV
1
5431
6
2)(
15
…
16
…
17
…
18
… …
19
°
°
20
…
21
… …
22
… …
23
Ω
… …
24
… …
°
°
25
… …27
26
© 28
