Positive electrode material of lithium-ion battery and preparation method therefor
摘要
說明書
The activated battery samples were subjected to a specified number of charge and discharge cycles, such as 80 cycles, at a current density of 1 C, a voltage range of 3.0-4.3 V and a temperature of 45° C. The specific discharge capacity at each cycle was obtained for calculating capacity retention. The capacity retention=the specific discharge capacity at the specified cycle/the initial specific discharge capacity*100%.
(3) Rate Performance.
The activated battery samples were subjected to charge and discharge cycles at current rates of 0.1 C, 0.2 C, 0.33 C, 0.5 C and 1 C respectively, at a voltage range of 3.0-4.3 V and room temperature, to obtain the specific discharge capacity at different rates.
(4) Lithium Ion Transference Number.
The lithium ion transference number was tested by EIS testing. In particular, the inactivated battery sample was set for 2 hours, charged at a constant current density of 0.1 C to a cut-off voltage of 4.3 V, charged at a constant voltage for 30 minutes, discharged at a constant current of 0.1 C to a cut-off voltage of 3.0 V, and then charged at a constant current density of 0.1 C to a cut-off voltage of 4.3 V, to obtain a fully charged battery sample. It was subjected to EIS testing at a frequency range of 100 kHz to 0.01 Hz, with an amplitude of 10 mV. According to the following equation, a slope, i.e. σ, of the fitted line of Zre to ω-? was obtained: Zre=Rs+Rct+σω??, and
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- ω=2πf,
