Electrochemical device and electronic device containing same
An electrochemical device includes a positive electrode, a negative electrode, and a separator. The negative electrode includes a negative active material. The negative active material includes at least one of silicon, tin, germanium, antimony, bismuth, and aluminum. The separator includes a porous substrate and a coating. The coating is located between the porous substrate and the negative electrode, and the coating includes a polymer binder. Based on a total weight of the coating, a weight percent of the polymer binder is 1%-100%, and a ratio of a weight of the polymer binder in the coating per unit area to a specific capacity of a corresponding component of the negative electrode per unit area is 0.00013 mg/mAh-0.00045 mg/mAh.
1 . An electrochemical device, comprising:
a positive electrode;
a negative electrode; and
a separator;
wherein the negative electrode comprises a negative active material, and the negative active material comprises a carbon material and an active component; the active component is at least one of simple substance, alloys or compounds of silicon; based on a total weight of the negative active material, a weight percentage of the active component being greater than or equal to 7% and less than 15%,
wherein the separator comprises a porous substrate and a coating, wherein the coating is located between the porous substrate and the negative electrode, and the coating comprises a polymer binder,
based on a total weight of the coating, a weight percentage of the polymer binder is 1%-100%, and a ratio of a weight of the polymer binder in the coating per unit area to a specific capacity of the active component of the negative electrode per unit area is 0.00015 mg/mAh-0.00045 mg/mAh,
the porous substrate includes at least one of polyolefin, polyamide, polyimide, polyester, or aramid fiber, and
the polymer binder comprises at least one of polyvinylidene fluoride, polyvinylidene difluoride-co-hexafluoropropylene, or polyvinylidene difluoride-co-trichloroethylene.
2 . The electrochemical device according to claim 1 , wherein a thickness of the coating is 0.5 μm-5 μm, a porosity of the coating is 20%-80%.
3 . The electrochemical device according to claim 1 , wherein a thickness of the porous substrate is in a range of 0.5 μm-5 μm.
4 . The electrochemical device according to claim 1 , wherein a porosity of the porous substrate is 20%-80%.
5 . The electrochemical device according to claim 1 , wherein the coating covers 20%-80% of the porous substrate.
6 . The electrochemical device according to claim 1 , wherein an adhesion force of the separator to the negative electrode is 2 N/m-30 N/m.
7 . The electrochemical device according to claim 1 , wherein the separator further comprises an inorganic coating, wherein the inorganic coating comprises inorganic particles, and the inorganic particles comprise at least one of SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , TiO 2 , and SiC.
8 . The electrochemical device according to claim 7 , wherein based on a total weight of the inorganic coating, a weight percentage of the inorganic particles is 1 wt %-100 wt %.
9 . The electrochemical device according to claim 7 , wherein the inorganic coating covers 1%-90% of the porous substrate.
10 . The electrochemical device according to claim 7 , wherein a thickness of the inorganic coating is 0.5 μm-5 μm.
11 . The electrochemical device according to claim 1 , wherein based on the total weight of the coating, the weight percent of the polymer binder is 20%-80%.
12 . An electronic device, comprising an electrochemical device, the electrochemical device comprises:
a positive electrode;
a negative electrode, wherein the negative electrode comprises a negative active material, and the negative active material comprises a carbon material and an active component, which is at least one of simple substance, alloys or compounds of silicon, based on a total weight of the negative active material, a weight percentage of the active component being greater than or equal to 7% and less than 15%; and
a separator, wherein the separator comprises:
a porous substrate and a coating, wherein the coating is located between the porous substrate and the negative electrode, and the coating comprises a polymer binder, and
based on a total weight of the coating, a weight percentage of the polymer binder is 1%-100%, and a ratio of a weight of the polymer binder in the coating per unit area to a specific capacity of the active component of the negative electrode per unit area is 0.00015 mg/mAh-0.00045 mg/mAh,
the porous substrate includes at least one of polyolefin, polyamide, polyimide, polyester, or aramid fiber, and
the polymer binder comprises at least one of polyvinylidene fluoride, polyvinylidene difluoride-co-hexafluoropropylene, or polyvinylidene difluoride-co-trichloroethylene.
13 . The electronic device according to claim 12 , wherein a thickness of the coating is 0.5 μm-5 μm, a porosity of the coating is 20%-80%.
14 . The electronic device according to claim 12 , wherein a thickness range of the porous substrate is 0.5 μm-5 μm.
15 . The electronic device according to claim 12 , wherein a porosity of the porous substrate is 20%-80%.
16 . The electronic device according to claim 12 , wherein a coverage of the coating on a first surface of the porous substrate is 20%-80%.
17 . The electronic device according to claim 12 , wherein an adhesion force of the separator to the negative electrode is 2 N/m-30 N/m.
18 . The electronic device according to claim 12 , wherein the separator further comprises:
inorganic coating, wherein the inorganic coating comprises inorganic particles, and the inorganic particles comprise at least one of SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , TiO 2 , and SiC.
19 . The electronic device according to claim 18 , wherein a coverage of the inorganic coating on the porous substrate is 1%-90%.
20 . The electronic device according to claim 18 , wherein a thickness of the inorganic coating is 0.5 μm-5 μm.