Abstract
Aqueous polysulfide/iodide redox flow batteries are attractive for scalable energy storage due to their high energy density and low cost. However, their energy efficiency and power density are usually limited by poor electrochemical kinetics of the redox reactions of polysulfide/iodide ions on graphite electrodes, which has become the main obstacle for their practical applications. Here, CoS2/CoS heterojunction nanoparticles with uneven charge distribution, which are synthesized in situ on graphite felt by a one-step solvothermal process, can significantly boost electrocatalytic activities of I−/I3 − and S2−/Sx 2− redox reactions by improving absorptivity of charged ions and promoting charge transfer. The polysulfide/iodide flow battery with the graphene felt-CoS2/CoS heterojunction can deliver a high energy efficiency of 84.5% at a current density of 10 mA cm−2, a power density of 86.2 mW cm−2 and a stable energy efficiency retention of 96% after approximately 1000 h of continuous operation.
| Original language | English |
|---|---|
| Article number | 3367 |
| Journal | Nature Communications |
| Volume | 10 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 1 2019 |
| Externally published | Yes |
Funding
This work was supported by National Natural Science Foundation of China (21771124, 21501120, 21331004 and 21673273), Science and Technology Commission of Shanghai Municipality (17ZR1441200), Shanghai Rising-Star Program (18QA1402400) and Scientific Innovation Talent of Henan Province (174200510017), National Science Foundation (Career Award, Grant No. 1847674), Utah State University Faculty start-up (to T.L.L.), the Utah Science Technology and Research initiative (USTAR) research award, and Utah Energy Triangle Faculty Award sponsored by the Utah State government. B.H. is grateful for China CSC Abroad Studying Fellowship and Utah Energy Triangle Student Award supported by the Utah State government.