Alloys Of Clathrate Allotropes For Rechargeable Batteries
AssigneeSouthwest Research Institute
InventorsCandace K. CHAN, Michael A. MILLER, Kwai S. CHAN
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Abstract
The present disclosure is directed at an electrode for a battery wherein the electrode comprises clathrate alloys of silicon, germanium or tin. In method form, the present disclosure is directed at methods of forming clathrate alloys of silicon, germanium or tin which methods lead to the formation of empty cage structures suitable for use as electrodes in rechargeable type batteries.
Claims18
An electrode for a battery wherein said electrode comprises clathrate alloys of silicon, germanium and/or tin.
A lithium-ion battery comprising an anode containing clathrate alloys of silicon, germanium and/or tin, a cathode and an electrolyte.
A method of forming Type I empty clathrate of silicon, germanium or tin, or alloy thereof, comprising the following scheme:
- n[R′—CH2—NR3]+Z−+[X′xX″y-x]n−→y[X′xX″46-x]0[Clathrate I]+n[R′═CH2]+nNR3+n/2H2
- R′=—(CH2)n—CH3;
- R3=—CH3, H;
- X′ or X″=Si, Ge, or Sn, and X′≠X″;
- Z=halogen or any other negatively charged counter-ion;
- y in [X′xX″y-x]n− and in y[X′xX″46-x]0=a number corresponding to a stable cluster size;
- n in [X′xX″y-x]n−=the formal charge of a stable cluster anion that depends on n, the starting number of moles of an alkyl ammonium salt;
- n in n[R′—CH2—NR3]+Z−=the starting number of moles of an alkyl ammonium salt;
- wherein R′ comprises any alkyl and/or branched alkyl and the value of n in R′=(CH2)n—CH3 is 1-50 and R′ when bonded to the indicated methylene group proceeds through a methine (—CH═) type linkage;
- and incorporating the following steps:
- (a) preparing an ionic liquid consisting of dodecyltrimethylammonium cation (DTMAC) and bis(trifluoromethylsulfonyl)imide anion (BTFMSI);
- (b) combining the said DTMAC-BTFMSI ionic liquid with alkali- or alkaline earth compounds of the metalloids Q(X′xX″2-x) or Q4(X′xX″9-x), where Q=Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, and Ra;
- and X′ or X″=Si, Ge, Sn, and X′≠X″, where x is an integer, a fraction, or a number plus a fractional part, to form the charged cluster [X′xX″y-x]n−;
- (c) in the absence of air or moisture, heating a reaction mixture of n[R′—CH2—NR3]+Z−+[X′xX″y-x]n−;
- (d) forming the Type I empty clathrate of the form [X′xX″46-x]0;
- x=0 to 46;
- (e) isolating the Type I empty clathrate product from the remaining liquid reaction mixture.
Dependencies are inferred from the claim text.