Mechanism and Solution for the Capacity Fading of Li/FeS₂Battery

Abstract

Development of Li/FeS 2 rechargeable batteries has been hampered by their short cycle life. In this paper, we start with the fundamental chemistry of FeS 2 in a non-aqueous liquid electrolyte to analyze the capacity fading mechanism of Li/FeS 2 batteries and propose three facile strategies for stabilizing capacity. It is repeatedly observed that the capacity fading of Li/FeS 2 cells follows a general mode consisting of a fast fading stage as Region 1, a slow fading stage as Region 2, and an accelerated fading stage as Region 3. We found that Region 1 is mainly attributed to the dissolution of lithium polysulfide leading to the loss of sulfur active material, and that Region 3 is mainly associated with the poor morphology of Li deposition resulting in the localized electric circuit shortening. The powder-like, small and loose Li particles not only react with electrolyte solvents drying-out the cell but also penetrate across the separator shortening the cell. Based on the above finding, the cycle life of Li/FeS 2 cells was improved by adding vinylene carbonate as the electrolyte additive, increasing mechanical pressure between two electrodes, and placing a carbon interlayer between the FeS 2 cathode and separator, respectively.

The application of nanostructured transition metal sulfides as anodes for lithium ion batteries

“…Similar conclusion is drawn by Zhang and Tran [111] , where ex-situ XRD and energy dispersive X-ray (EDX) analysis were conducted to study the reaction mechanism of FeS 2 /Li batteries ( Fig. 16 ).…”

Nanocrystalline Pyrite for Photovoltaic Applications

“…Pyrite has wide area of applications (Figure ) such as energy storage and conversion field: photovoltaics,, photocatalytic hydrogen production, batteries, supercapacitors, photocapacitors, thermoelectricity;, electronics,, optoelectronics, spintronics; environmental applications; hydrogenation; sensors; agriculture, and emerging biomedical field …”

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“…The depressed semicircles are assigned to the interfacial charge transfer resistance ( R ct ) [33,34] . The inclined line in the low frequency is designated to Warburg impedance ( Z w ), corresponding to ions diffusion into the bulk of the electrode [35,36] . The charge transfer resistance of FeS 2 /C nanospheres is much lower compared to that of FeS 2 nanospheres after 10 cycles.…”