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 anode active material on the current collector, said anode active material formed from an active material layer comprising:
a plurality of silicon particles; and
a pyrolytic carbon structure comprising a framework around the plurality of silicon particles of the active material,
wherein said active material layer has a silicon content greater than or equal to 50% by weight and said pyrolytic carbon structure comprises a pyrolytic carbon from pyrolysis of polyamide-imide (PAI); and
wherein the anode active material yields silicon constituting up to 92% of weight of a formed anode after pyrolysis.
2 . The anode according to claim 1 , where the anode has been subjected to heating at or above 400° C.
3 . The anode according to claim 1 , wherein the pyrolytic carbon structure comprises between 2% and 6% by weight of the anode after pyrolysis below 600° C.
4 . The anode according to claim 3 , wherein the pyrolytic carbon structure comprises between 4% and 5% by weight of the anode after pyrolysis below 600° C.
5 . The anode according to claim 1 , wherein an onset of pyrolysis occurs below 500° C.
6 . The anode according to claim 1 , wherein pyrolysis produces carbonization of the PAI below 600° C.
7 . The anode according to claim 1 , wherein:
the active material layer further comprises a carbon-based additive.
8 . The anode according to claim 7 , wherein said carbon-based additive comprises at least one of ECP, ECP600, Super-P, and SLP.
9 . The anode of claim 1 , wherein:
the current collector comprises copper; and
an interface between the current collector and the active material layer lacks a formation of CuxSi material.
10 . The anode of claim 1 , wherein:
the current collector comprises nickel; and
an interface between the current collector and the active material layer lacks a formation of NixSi material.
11 . 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 anode active material on the current collector, said anode active material formed from an active material layer comprising:
a plurality of silicon particles; and
a pyrolytic carbon structure comprising a framework around the plurality of silicon particles of the active material,
wherein said active material layer has a silicon content greater than or equal to 50% by weight and said pyrolytic carbon structure comprises a pyrolytic carbon from pyrolysis of polyamide-imide (PAI); and
wherein the anode active material yields silicon constituting up to 92% of weight of a formed anode after pyrolysis.
12 . The battery according to claim 11 , where the anode has been subjected to heating at or above 400° C.
13 . The battery according to claim 12 , wherein the pyrolytic carbon structure comprises between 2% and 6% by weight of the anode after pyrolysis below 600° C.
14 . The battery according to claim 13 , wherein the pyrolytic carbon structure comprises between 4% and 5% by weight of the anode after pyrolysis below 600° C.
15 . The battery according to claim 11 , wherein an onset of pyrolysis occurs below 500° C.
16 . The battery according to claim 11 , wherein pyrolysis produces carbonization of the PAI below 600° C.
17 . The battery according to claim 11 , wherein:
the active material layer further comprises a carbon-based additive.
18 . The battery according to claim 17 , wherein said carbon-based additive comprises at least one of ECP, ECP600, Super-P, and SLP.
19 . The battery of claim 11 , wherein:
the current collector comprises copper; and
an interface between the current collector and the active material layer lacks a formation of CuxSi material.
20 . The battery of claim 11 , wherein:
the current collector comprises nickel; and
an interface between the current collector and the active material layer lacks a formation of NixSi material.