Lower pyrolysis temperature binder for silicon-dominant anodes
Systems and methods are provided for carbon additives for direct coating of silicon-dominant anodes. An example composition for use in directly coated anodes may include a silicon-dominated anode active material, a carbon-based binder, and a carbon-based additive, with the composition being configured for low-temperature pyrolysis. The low-temperature pyrolysis may be conducted at <600° C. An anode may be formed using a direct coating process of the composition on a current collector. The anode active material yields silicon constituting between 86% and 97% of weight of the formed anode after pyrolysis. The carbon-based additive yields carbon constituting between 2% and 6% of weight of the formed anode after pyrolysis.
1. An anode, the anode comprising:
a current collector; and
an active material layer on the current collector, the active material layer comprising:
a plurality of silicon particles providing the anode with a silicon content of greater than 94% and up to 97% by weight of the anode; and
a pyrolytic carbon structure comprising a framework around the plurality of silicon particles of the active material layer,
wherein the pyrolytic carbon structure comprises between 4% and 5% of the weight of the anode after pyrolysis below 600° C.
2. The anode according to claim 1 , wherein a battery comprises the anode.
3. The anode according to claim 1 , wherein the pyrolytic carbon structure comprises a glassy carbon from pyrolysis of polyamide-imide (PAI).
4. The anode according to claim 3 , wherein an onset of pyrolysis occurs below 500° C.
5. The anode according to claim 4 , wherein pyrolysis produces carbonization of the PAI below 600° C.
6. The anode according to claim 3 , wherein:
the active material layer comprises a carbon-based additive; and
the carbon-based additive comprises between 2% and 6% of weight of the anode after pyrolysis below 600° C.
7. The anode according to claim 1 , wherein:
the active material layer comprises an additive; and
the additive comprises at least one of ECP, ECP600, Super-P, and SLP.
8. A battery, comprising:
an anode;
a cathode; and
a separator between the anode and the cathode,
wherein the anode comprises a current collector and an active material layer on the current collector;
wherein the active material layer comprises a silicon content of greater than 94% and up to 97% by weight of the anode;
wherein the active material layer comprises a pyrolytic carbon framework; and
wherein the pyrolytic carbon structure comprises between 4% and 5% of the weight of the anode after pyrolysis below 600° C.
9. The battery according to claim 8 , wherein the pyrolytic carbon framework comprises glassy carbon from pyrolytic decomposition of polyamide-imide (PAI).
10. The battery according to claim 9 , wherein an onset of decomposition occurs below 500° C.
11. The battery according to claim 9 , wherein carbonization of the PAI occurs below 600° C.
12. The battery according to claim 8 , wherein:
the active material layer comprises a carbon-based additive; and
the carbon-based additive comprises between 2% and 6% of weight of the anode.
13. The battery according to claim 8 , wherein:
the active material layer comprises an additive; and
the additive comprises at least one of ECP, ECP600, Super-P, and SLP.