Method And System For Safety Of Silicon Dominant Anodes
Systems and methods provide for safety of silicon dominant anodes in a battery. The battery may include an anode comprising an anode active material layer on a metal current collector, where the anode active material layer comprises pyrolyzed binder, conductive additives, and 50% or more silicon by weight. The battery may further include a separator, an electrolyte, a cathode, and a solid electrolyte interface between the anode active material layer and the electrolyte, and has a thermal runaway temperature of greater than 260° C. The conductive additives may comprise between 1% and 40% of the active material layer. The anode active material layer may comprise between 20% to 95% silicon. The separator may comprise ceramic-coated polyolefin or polymer-coated polyolefin. The electrolyte may comprise Lithium hexafluorophosphate (LiPF 6 ) and/or lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in one or more electrolyte solvents. The metal current collector may comprise copper.
1 . A battery comprising:
an anode comprising an anode active material layer on a metal current collector, the anode active material layer comprising pyrolyzed binder, conductive additives, and 50% or more silicon by weight;
a separator;
an electrolyte;
a cathode; and
a solid electrolyte interface between the anode active material layer and the electrolyte;
wherein a composition of one or both of the anode and the electrolyte and/or a formation process of the battery are configured such that the battery has a thermal runaway temperature of greater than 200° C.
2 . The battery according to claim 1 , wherein the conductive additives comprise between 1% and 40% of the active material layer by weight.
3 . The battery according to claim 1 , wherein the anode active material layer comprises between 20% to 95% silicon by weight.
4 . The battery according to claim 1 , wherein the separator comprises ceramic-coated polyolefin.
5 . (canceled)
6 . The battery according to claim 1 , wherein the electrolyte comprises 20% or more FEC by weight.
7 . The battery according to claim 1 , wherein upon heating, the anode does not go into thermal runaway before the cathode.
8 . (canceled)
9 . The battery according to claim 1 , wherein the battery does not go into thermal runaway when punctured by a nail.
10 . The battery according to claim 1 , wherein a temperature of the battery when punctured by a nail does not rise by more than 2° C.
11 . The battery according to claim 1 , wherein the battery has a thermal runaway temperature of greater than 260° C.
12 . A method for battery safety, the method comprising providing a battery comprising an anode comprising an anode active material layer on a metal current collector, the anode active material layer comprising pyrolyzed binder, conductive additives, and 50% or more silicon by weight;
a separator;
an electrolyte;
a cathode; and
a solid electrolyte interface between the anode active material layer and the electrolyte;
wherein a composition of one or both of the anode and the electrolyte and/or a formation process of the battery are configured such that the battery has a thermal runaway temperature of greater than 200° C.
13 . The method according to claim 12 , wherein the conductive additives comprise between 1% and 40% of the active material layer by weight.
14 . The method according to claim 12 , wherein the anode active material layer comprises between 20% to 95% silicon by weight.
15 . The method according to claim 12 , wherein the separator comprises ceramic-coated polyolefin.
16 . (canceled)
17 . The method according to claim 12 , wherein the electrolyte comprises 20% or more FEC by weight.
18 . (canceled)
19 . The method according to claim 12 , wherein upon heating, the anode does not go into thermal runaway before the cathode.
20 . The method according to claim 12 , wherein the battery does not go into thermal runaway when punctured by a nail.
21 . The method according to claim 12 , wherein a temperature of the battery when punctured by a nail does not rise by more than 2° C.
22 . The method according to claim 12 , wherein the battery has a thermal runaway temperature of greater than 260° C.
23 . (canceled)
24 . The battery according to claim 1 , wherein:
wherein the electrolyte comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in one or more electrolyte solvents; and
the LiTFSI is present at concentration of about 0 to 2.0 molar (M).
25 . The method according to claim 12 , wherein:
wherein the electrolyte comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in one or more electrolyte solvents; and
providing the LiTFSI such that when present the LiTFSI is at concentration of about 0 to 2.0 molar (M).
26 . The battery according to claim 1 , wherein upon heating, the solid electrolyte interface does not begin to decompose until 60+/−5° C.
27 . The method according to claim 12 , wherein upon heating, the solid electrolyte interface does not begin to decompose until 60+/−5° C.