Lithium battery
Disclosed is a lithium battery including a silicon negative electrode, a lithium mixed metal oxide positive electrode, a separator disposed between the negative and positive electrodes to define a reservoir region, an electrolytic solution filled in the reservoir region, and a sealant structure wrapped around the silicon negative electrode, the lithium mixed metal oxide positive electrode, the separator, and the electrolytic solution. The electrolytic solution includes an organic solvent, a lithium salt, and an additive. The additive includes a maleimide compound and vinylene carbonate. The silicon negative electrode of the lithium battery employing the described electrolytic solution has higher cycle efficiency and longer operating lifespan.
1. A lithium battery, comprising:
a silicon negative electrode;
a lithium mixed metal oxide positive electrode;
a separator disposed between the silicon negative electrode and the lithium mixed metal oxide positive electrode to define a reservoir region;
an electrolytic solution filled in the reservoir region; and
a sealant structure wrapped around the silicon negative electrode, the lithium mixed metal oxide positive electrode, the separator, and the electrolytic solution,
wherein the electrolytic solution comprises:
an organic solvent;
a lithium salt; and
an additive comprising:
maleimide, bismaleimide, a polymaleimide, a polybismaleimide, a copolymer of maleimide and bismaleimide, or mixtures thereof, and
vinylene carbonate;
wherein the maleimide is, N-(o-methylphenyl) maleimide, N-(m-methylphenyl) maleimide, N-(p-methylphenyl) maleimide, N-cyclohexylmaleimide, maleimidophenol, maleimidobenzocyclobutene, phosphorus-containing maleimide, phosphonate-containing maleimide, siloxane-containing maleimide, N-(4-tetrahydropyranyl-oxyphenyl) maleimide, or 2,6-xylylmaleimide.
2. The lithium battery as claimed in claim 1 , wherein the organic solvent comprises: γ-butyrolactone, ethylene carbonate, propylene carbonate, diethyl carbonate, propyl acetate, dimethyl carbonate, ethylmethyl carbonate, or combinations thereof.
3. The lithium battery as claimed in claim 1 , wherein the lithium salt comprises: LiPF 6 , LiBF 4 , LiAsF 6 , LiSbF 6 , LiClO 4 , LiAlCl 4 , LiGaCl 4 , LiNO 3 , LiC(SO 2 CF 3 ) 3 , LiN(SO 2 CF 3 ) 2 , LiSCN, LiO 3 SCF 2 CF 3 , LiC 6 F 5 SO 3 , LiO 2 CCF 3 , LiSO 3 F, LiB(C 6 H 5 ) 4 , LiCF 3 SO 3 , or combinations thereof.
4. The lithium battery as claimed in claim 1 , wherein the bismaleimide is represented by formula as below:
wherein R comprises
5. The lithium battery as claimed in claim 1 , wherein the silicon negative electrode is composed of a silicon powder, and the surface of the silicon powder is further covered by a carbon film.
6. The lithium battery as claimed in claim 5 , wherein the carbon film to the silicon powder has a weight ratio of 10 wt % to 50 wt %.
7. The lithium battery as claimed in claim 1 , wherein the lithium mixed metal oxide positive electrode comprises: LiMnO 2 , LiMn 2 O 4 , LiCoO 2 , Li 2 Cr 2 O 7 , Li 2 CrO 4 , LiNiO 2 , LiFeO 2 , LiNi x Co 1-x O 2 , LiFePO 4 , LiMn 0.5 Ni 0.5 O 2 , LiMn 1/3 Co 1/3 Ni 1/3 O 2 , LiMc 0.5 Mn 1.5 O 4 , or combinations thereof, wherein 0<x<1 and Mc is a divalent metal.
8. The lithium battery as claimed in claim 1 , wherein the lithium mixed metal oxide positive electrode further comprises a polymer binder, and the polymer binder comprises: poly(vinyliden fluoride), styrene-butadiene rubber, polyamide, melamine resin, or combinations thereof.
9. The lithium battery as claimed in claim 1 , wherein the separator comprises: polyethylene, polypropylene, or combinations thereof.