1. Volume 1, Issue 2, Pages 359-370 (October 2017)
Li-CO2 Electrochemistry: A New Strategy for CO2 Fixation and Energy Storage 
Yu Qiao, Jin Yi, Shichao Wu, Yang Liu, Sixie Yang, Ping He, Haoshen Zhou 
Joule 
Volume 1, Issue 2, Pages (October 2017)
DOI: /j.joule
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2. Joule 2017 1, DOI: ( /j.joule )
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3. Figure 1
Characterizations and Schematic of the Electrochemical CO2 Reduction Process
(A and B) Galvanostatic discharge profiles of the Li-CO2 cell with a configuration of (sputtered gold cathode)/(CO2-saturated 0.5 M LiClO4-DMSO electrolyte)/lithium foil. The current is 5 μA and the capacity is limited at 10 μAh (A) and 20 μAh (B), respectively.
(C and D) Capacity-dependent in situ Raman spectra recorded during the corresponding discharge processes above: 10 μAh (C) and 20 μAh (D) cut-off capacity, respectively. Spectra collected on different discharge plateaus are separated by different colors (red and blue). In situ Raman peak intensities for Li2CO3 (1,085 cm−1), carbon (G band, 1,587 cm−1), and Li2O (521 cm−1) are demonstrated in the corresponding voltage profile (insert), respectively.
(E) SEM images of the cathodes harvested at various discharge depths, in comparison with the pristine cathode.
(F) The schematic for the achievement of CO2 fixation via Li-CO2 electrochemistry technology.
Joule 2017 1, DOI: ( /j.joule )
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4. Figure 2
In Situ Raman Evidence for the Rechargeable/Irreversible Li-CO2 Electrochemistry Process with Solo Decomposition of Li2CO3 during Charging
(A and B) Capacity-dependent in situ Raman spectra collected during charging at a constant current of 5 μA after discharge to different cut-off capacities: 10 μAh (A) and 20 μAh (B). The spectra are offset for clarity and different colors (red and blue) are used to distinguish the various charge plateaus.
(C) In situ Raman spectra observed at the end of each discharge (bottom)/charge (top) process during cycling under a fixed capacity of 10 μAh. Corresponding voltage profiles are listed above each group of the in situ spectra.
The asterisk (*) indicates the peaks assigned to the dimethyl sulfone (DMSO2) species observed during charging.
Joule 2017 1, DOI: ( /j.joule )
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5. Figure 3
Characterization of the Discharge/Charge Processes Conducted with a Practical Porous Carbon Cathode
(A) Voltage profile of a Li-CO2 cell with a discharge capacity limitation of 1.0 mAh and charge cut-off voltage of 4.5 V at a current density of 100 mA g−1.
(B) Ex situ FTIR spectra performed on the cathode collected at different discharge/charge stages marked by varying colors for clarity.
(C) CO2 gas evolution rate during carbonate quantification conducted on a cathode discharged at 0.6 mAh (point B). Blue arrow corresponds to the injection of H2SO4 to decompose Li2CO3. The yield shown on the inset pie chart indicates the percentage of fixed Li2CO3 species (obtained by the area integral of the CO2 evolution rate) versus the quantity of reduced CO2 (calculated based on the discharge capacity).
(D–F) DEMS results of gas evolution rates for CO2 and O2 during cell charging: at (D) 500 mA g−1 and (E) 2000 mA g−1 current density after discharged to point-B; (F) 500 mA g−1 after discharged to point-C. The electron number (versus CO2/O2 gas molecule) marked with the dashed lines correspond to the related reaction pathways.
Joule 2017 1, DOI: ( /j.joule )
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6. Figure 4
Characterization and Schematic of the Rechargeable/Reversible Li-CO2 Electrochemistry Process Achieved on the Ruthenium-Based Cathode
(A) Galvanostatic discharge/charge profile of the Li-CO2 cell with the Ru-based cathode. The charge profile conducted on the Au-based cathode is shown for comparison.
(B) Capacity-dependent in situ Raman spectra collected on the Ru-based cathode during the charge process.
(C and D) Linear potential scan at 10 mV s−1 between 3.0 and 4.5 V conducted at both of the Ru (C) and Au (D) cathodes after galvanostatic discharge, respectively. Capacity dependence of the Raman peak intensity at 1,085 cm−1 (Li2CO3) and 1,587 cm−1 (G band of carbon) observed on both cathodes are also shown for each of the current profiles. Note that the error bars for each peak intensity are as obtained based on parallel experiments (3 times).
(E) Schematic for the achievement of an energy storage system (reversible process) and a CO2 fixation strategy (irreversible process) via Li-CO2 electrochemistry technology.
Joule 2017 1, DOI: ( /j.joule )
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