Silicon particles for active materials and electro-chemical cells are provided. The active materials comprising silicon particles described herein can be utilized as an electrode material for a battery. In certain embodiments, the composite material includes greater than 0% and less than about 90% by weight silicon particles, the silicon particles having an average particle size between about 10 nm and about 40 μm, wherein the silicon particles have surface coatings comprising silicon carbide or a mixture of carbon and silicon carbide, and greater than 0% and less than about 90% by weight of one or more types of carbon phases, wherein at least one of the one or more types of carbon phases is a substantially continuous phase.

A composition of matter defined by the general formula of M.sub.2+vL.sub.1−vX.sub.2, wherein: X is carbon; M represents a transition metal selected from the group consisting of Ti, Ta, Sc, Cr, Zr, Mo, V, and Nb; and L represents a lanthanide element selected from the group consisting of Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

A Composition of matter defined by the general formula of M1M2M3M4X.sub.3 wherein: X is carbon; and M1, M2, M3, and M4 each represent a different transition metal selected from the group consisting of Ti, Ta, Sc, Cr, Zr, Hf, Mo, V, and Nb.

Silicon particles for active materials and electro-chemical cells are provided. The active materials comprising silicon particles described herein can be utilized as an electrode material for a battery. In certain embodiments, the composite material includes greater than 0% and less than about 90% by weight silicon particles, the silicon particles having an average particle size between about 10 nm and about 40 μm, wherein the silicon particles have surface coatings comprising silicon carbide or a mixture of carbon and silicon carbide, and greater than 0% and less than about 90% by weight of one or more types of carbon phases, wherein at least one of the one or more types of carbon phases is a substantially continuous phase.

Silicon particles for active materials and electro-chemical cells are provided. The active materials comprising silicon particles described herein can be utilized as an electrode material for a battery. In certain embodiments, the composite material includes greater than 0% and less than about 90% by weight silicon particles, the silicon particles having an average particle size between about 10 nm and about 40 μm, wherein the silicon particles have surface coatings comprising silicon carbide or a mixture of carbon and silicon carbide, and greater than 0% and less than about 90% by weight of one or more types of carbon phases, wherein at least one of the one or more types of carbon phases is a substantially continuous phase.

Bisaminoalkoxysilanes of Formula I, and methods using same, are described herein:
R.sup.1Si(NR.sup.2R.sup.3)(NR.sup.4R.sup.5)OR.sup.6  I
where R.sup.1 is selected from hydrogen, a C.sub.1 to C.sub.10 linear alkyl group, a C.sub.3 to C.sub.10 branched alkyl group, a C.sub.3 to C.sub.10 cyclic alkyl group, a C.sub.3 to C.sub.10 alkenyl group, a C.sub.3 to C.sub.10 alkynyl group, a C.sub.4 to C.sub.10 aromatic hydrocarbon group; R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are each independently selected from hydrogen, a C.sub.4 to C.sub.10 branched alkyl group, a C.sub.3 to C.sub.10 cyclic alkyl group, a C.sub.3 to C.sub.10 alkenyl group, a C.sub.3 to C.sub.10 alkynyl group, and a C.sub.4 to C.sub.10 aromatic hydrocarbon group; R.sup.6 is selected from a C.sub.1 to C.sub.10 linear alkyl group, a C.sub.3 to C.sub.10 branched alkyl group, a C.sub.3 to C.sub.10 cyclic alkyl group, a C.sub.3 to C.sub.10 alkenyl group, a C.sub.2 to C.sub.10 alkynyl group, and a C.sub.4 to C.sub.10 aromatic hydrocarbon group.

Bisaminoalkoxysilanes of Formula I, and methods using same, are described herein:
R.sup.1Si(NR.sup.2R.sup.3)(NR.sup.4R.sup.5)OR.sup.6  I
where R.sup.1 is selected from hydrogen, a C.sub.1 to C.sub.10 linear alkyl group, a C.sub.3 to C.sub.10 branched alkyl group, a C.sub.3 to C.sub.10 cyclic alkyl group, a C.sub.3 to C.sub.10 alkenyl group, a C.sub.3 to C.sub.10 alkynyl group, a C.sub.4 to C.sub.10 aromatic hydrocarbon group; R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are each independently selected from hydrogen, a C.sub.4 to C.sub.10 branched alkyl group, a C.sub.3 to C.sub.10 cyclic alkyl group, a C.sub.3 to C.sub.10 alkenyl group, a C.sub.3 to C.sub.10 alkynyl group, and a C.sub.4 to C.sub.10 aromatic hydrocarbon group; R.sup.6 is selected from a C.sub.1 to C.sub.10 linear alkyl group, a C.sub.3 to C.sub.10 branched alkyl group, a C.sub.3 to C.sub.10 cyclic alkyl group, a C.sub.3 to C.sub.10 alkenyl group, a C.sub.2 to C.sub.10 alkynyl group, and a C.sub.4 to C.sub.10 aromatic hydrocarbon group.

The present disclosure relates to a method for producing a metal carbide, where the method includes thermally treating a molecular precursor in an oxygen-free environment, such that the treating produces the metal carbide and the molecular precursor includes

##STR00001##

where M is the metal of the metal carbide, N* includes nitrogen or a nitrogen-containing functional group, and x is between zero and six, inclusively.

The present disclosure relates to a method for producing a metal carbide, where the method includes thermally treating a molecular precursor in an oxygen-free environment, such that the treating produces the metal carbide and the molecular precursor includes

##STR00001##

where M is the metal of the metal carbide, N* includes nitrogen or a nitrogen-containing functional group, and x is between zero and six, inclusively.

The present disclosure is directed to electroacoustical devices comprising patterned MXene compositions on biaxially oriented polymer substrates and methods of making and using the same.