Lithium - Sulfur Battery Cathode Material Based On Cluster - Like Molecules
- Dec 13, 2018 -
Recently, professor dong quan-feng from the school of chemistry and chemical engineering of xiamen university and professor Leroy Cronin from the university of Glasgow made new progress in the study of li-sulfur batteriesClusters about in JACS (DOI: 10.1021 / JACS. 8 b0041) prior to that, professor dong group of lithium sulfur batteries sulfur composite anode materials for the research of the system in the early by in situ Raman technology combined with the theoretical calculation to explore the reaction mechanism of lithium sulfur batteries, confirmed to the load of s-based body material doped nitrogen modification can be complete with elemental sulfur as the positive active material charge and discharge cycle (Chem. Mater., 2015, 27, 2048?2055);Subsequently, the synergistic catalytic effect of co-n was successfully applied to the REDOX process of S for the first time, and the multi-functional and bicatalytic concepts were proposed (EES, 2016, 9, 1998-2004).On the basis of improving the sulfur content of composite anode materials, the research group prepared non-carbon mesoporous Co4N microspheres for the first time to achieve up to 95% sulfur loading capacity (ACS Nano, 2017, 11, 6031-6039). POMs is a kind of molecular cluster material with nano-size and the characteristics of reversible multi-electron reaction.Is referred to as the electronic image of the sponge, because it can be reversible storage of ions and electrons, which has become a higher specific capacity of energy storage materials, the feasibility of the research for the first time in clusters of polymetallic oxygen sour salt lithium battery cathode substrate material, the material (K3 [H3AgIPW11O39]) with lewis acid and lewis base in the meantime, thus has the function of double loci adsorption polysulphide can realize effective control of sulphur electrochemical reaction processExperimental results and DFT theoretical calculations show that Ag(I) hetero-metal ions can regulate the adsorption of polysulphides and end-point oxygen atoms to lithium ions in the framework structure of polyanions, and that lithium sulfur batteries prepared with Ag(I) as the framework material exhibit excellent electrochemical properties.
Schematic diagram of Li2S produced by the lithium sulfur battery system absorbed by POMs
The optimized structure of adsorption gibbs free energy difference (train Gads) and Li2Sn (n = 8, 6, 4) combined with PW12O40 and K3 [H3AgIPW11O39] clusters was calculated
Raman spectra and optical photographs of A, B, C, D and E
A: blank solution of DME/DOXL;
B: DME/DOXL solution of Li2S6;
C: DME/DOXL solution of Li2S6 and superconductive carbon black;
D: DME/DOXL solution of Li2S6 and PW12O40;
E: DME/DOXL solution of Li2S6 and AgIPW11O39.
Electrochemical characterization of AgPW11 / S electrode
A) : discharge - charging curve of AgPW11 / S electrode at different rates;
B) battery cycle test of AgPW11 / S, K3PW12O40 / S and super-conductive carbon black/S electrode li-sulfur battery at a rate of 1C;
C) : AgPW11 / S electrode and super-conductive carbon black/S long battery cycle at a rate of 2C.