High-rate, high-density FeSb–TiC–C nanocomposite anodes for lithium-ion batteries

Abstract

High-density, high-rate FeSb-TiC-C nanocomposite alloy anodes composed of varying amounts of FeSb, TiC, and conductive carbon black have been synthesized by heating the metallic precursors first followed by high-energy mechanical milling (HEMM) of the product with carbon black. The synthesis method allows for a systematic variation of the TiC and carbon contents within the electrode so that the effects of each component on the electrochemical performance can be understood. The FeSb-TiC-C samples display high tap density (2.9 g cm À3 ), high reversible specific capacity (450 mA h g À1 ), superior volumetric capacity (1300 mA h cm À3 ), and high rate capability (89% retention of the C/5 capacity at 10 C rate).However, realizing a cycle life of >500 cycles requires increased contents of carbon and TiC, which lead to a reduction in reversible capacity and tap density. Incorporation of additives, such as fluoroethylene carbonate (FEC) or vinylene carbonate (VC), into the electrolyte provides moderate improvements in cycle life. The FeSb-TiC-C nanocomposite anodes with a high volumetric capacity at a moderate operating voltage offer an attractive alternative to graphite anodes with safety advantages.

FeSn2–TiC nanocomposite alloy anodes for lithium ion batteries

“…Neither FeSn 2 eTiC nor SneTiC have carbon black as a final component in their composite structure and they exhibit much lower first cycle losses than FeSn 2 eC, which has carbon black. This is in agreement with previous studies attributing higher first cycle irreversibility to carbon black in composite electrodes [25]. In addition, the use of FeSn 2 intermetallic instead of Sn as the active material results in significant increase in capacity retention as demonstrated by the higher capacity values at 100 cycles for both FeSn 2 eTiC and FeSn 2 eC relative to SneTiC.…”

“…Similar capacity fade has been observed in previous studies of alloying anode materials where carbon black was the reinforcing phase [25]. The FeSn 2 eTiC material demonstrates both good early cycling as well as stable capacity for 100 cycles.…”

“…Ceramics employed in these composites are frequently oxides such as Al 2 O 3 or carbides such as TiC [24,25,27e29]. The reinforcing ceramic of TiC was selected for this study for a number of reasons: it has demonstrated the capability to effectively increase the cycle life of alloying anodes; it is a highly conductive ceramic material, so it can also aid in electrical conductivity of the electrode; it has a higher density that can yield greater volumetric electrode capacity; it has produced composites with lower first cycle losses than competing carbon composites [24,25].…”

Highly stable cycling of a lead oxide/copper nanocomposite as an anode material in lithium ion batteries

“…9 Under air and reducing agents, lead ions form lead oxide and copper without further oxidation (eqn (2)). 9 Under air and reducing agents, lead ions form lead oxide and copper without further oxidation (eqn (2)).…”

“…Metal oxides usually exhibit low volume changes during cycling, and the rst lithiation forms metal clusters surrounded by lithium oxides and lithium metal alloys that act as buffer layers for accommodating the cyclic volume changes, thus possibly enhancing cycling performance. 9 However, depositing an even carbon coating on metal oxide surfaces is not possible at the molecular level. For example, Li et al reported the one-step hydrothermal synthesis of Nb 2 O 5 /carbon composites with enhanced electrochemical performance (specic capacity ¼ 100 mA h g À1 at a current density of 500 mA g À1 ).…”