Figure 6. (a) Cycling performance of
Li/ZSONT/CC//LiFePO4(LFP), Li/Cu//LFP, and Li/CC//LFP
cells at 2C. (b) Charging/discharging curves of Li/ZSONT/CC//LFP,
Li/Cu//LFP and Li/CC//LFP cells in the 100th and
200th cycle. (c) Rate performance of Li/ZSONT/CC//LFP,
Li/Cu//LFP and Li/CC//LFP batteries cycled from 0.2 to 5C. (d) Cycling
performance of high-loading Li/ZSONT/CC//LFP, Li/Cu//LFP and Li/CC//LFP
batteries at 2C (cathode loading=7.0mg cm-2, N:
P=4.8).
To demonstrate the practical application of ZSONT/CC host,
Li/ZSONT/CC//LiFePO4 (LFP) cells (with 4 mA h
cm-2 Li) were assembled using ester-based electrolyte.
For comparison, Li/Cu//LFP and Li/CC//LFP full cells were also assembled
with the same parameters. As depicted in Figure 6a ,
Li/ZSONT/CC//LFP cell delivered excellent cycle stability with retaining
capacity up to 77 mA h g-1 (with a capacity retention
of 71%) after 4000 cycles at 2C, exhibiting a high average CE of
99.2%. In contrast, Li/Cu//LFP cell showed a fast capacity degradation
and a low-capacity retention of 33.2% after 200 cycles, and Li/CC//LFP
cell dropped to 71 mA h g-1 after 725 cycles (with a
capacity retention of 66.5%). Figure 6b showed the
charge/discharge curves of two full cells in the 100thcycle and 200th cycle. Although the voltage plateau
gap of the three cells was similar in the 100th cycle,
a much smaller polarization voltage was observed in Li/ZSONT/CC//LFP
full cell after 200 cycles. Besides, Li/ZSONT/CC//LFP full cell
exhibited a superior rate performance to the other two (Fig.
6c ), especially at large rates, the specific capacities of
Li/ZSONT/CC//LFP full cell can reach up to 104.9 mA h
g-1 at 5C, much better than Li/Cu//LFP ( 92.3 mA h
g-1 at 5C ) and Li/CC//LFP ( 95.4 mA h
g-1 at 5C). Moreover, an N/P ratio of 4.8 with 7mg
cm-2 LFP was chosen for the full cell that was cycled
(Fig. 6d ) at a charging/discharging rate of 2C. The cell can
run for over 300 cycles with little capacity decay, demonstrating
excellent cycling performance. As a comparison, Li/Cu//LFP full cell
showed a lifespan of 70 cycles, and the capacity of Li/CC//LFP full cell
faded to 45.8 mA h g-1 at the end of 300 cycles.