6/14/2024
Voltage ranges EA0
Half-cells:
• LFP vs. Li: 2.7–4.1 V | Our experiment: 2.5 – 4 V
• Graphite vs. Li: 0.005–1.5 V |Our experiment: 0.005 – 1.5 V
Full cells:
• LFP vs. Graphite: 2.2–4.1 V
Definitions
‒ Lithiation:
The process of lithium ions being incorporated into the anode material during
charging of a full cell
‒ Delithiation:
The process of lithium ions being extracted from the anode material during
discharging of a full cell
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Slide 1
EA0 how do we calculate them?
Efthymiadou Anastasia, 2024-06-08T15:20:16.213
6/14/2024
Definitions
‒ Cathode:
The cathode is the electrode where reduction (gain of electrons) occurs
‒ Anode:
The anode is the electrode where oxidation (loss of electrons) occurs
Definitions
‒ Positive electrode:
The electrode with a positive electrical potential relative to the other
electrode in the cell
‒ Negative electrode:
The electrode with a negative electrical potential relative to the other electrode
in the cell
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Full cell
Graphite
KS44 / SFG6
0.005-1.5 V
Anode ‒
Charge / lithiation
Cathode +
LFP
2.5-4.0 V
Lithiation/charge Lithium ferrous phosphate
Delithiation /discharge
Battery charge/discharge
Provides energy
Draws energy to battery
from battery
spontaneous reaction
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Half-cells
Anode: Graphite vs. Li Cathode: LFP vs. Li
0 V Li+ vs. Li ‒ 0 V Li+ vs. Li
‒
lithiation power lithiation power
supply supply
+ +
KS44 / SFG6 LFP
0.005-1.5 V 2.5-4.0 V
apply negative current apply positive current
for first half-cycle (charge) for first half-cycle (charge)
Potential vs. time
Cyclic Voltammetry (CV)
• Potential V ramps linearly versus
time t
• The rate of voltage change over Normalized current vs. time
time during each of these phases is
known as the experiment's scan
rate (V/s) / sweep rate
• The cyclic voltammogram is a
current response plotted as a
function of the applied potential
• Area under current – charge Q for Normalized current vs. potential
each reaction
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6/14/2024
Constant Voltage - Constant Current (CCCV)
CC-CV charging mode:
The charging current is held
constant until a preset point,
after which the voltage is kept
constant while the charging
current decreases
