Electrochemical apparatus and electronic apparatus including same
An electrochemical apparatus, including an electrolyte and a positive electrode, where the electrolyte includes ethylene carbonate and propylene carbonate, the positive electrode includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, and the positive electrode active material layer includes a positive electrode active material, where percentages of ethylene carbonate and propylene carbonate satisfy a specific relationship, and under an X-ray diffraction (XRD) test, a peak intensity I 003 of plane 003 of the positive electrode active material layer and a peak intensity I 104 of plane 104 of the positive electrode active material layer satisfy a specific relationship. With the above configuration, the electrochemical apparatus of this application shows excellent performances, especially the high-temperature floating charge performance.
1 . An electrochemical apparatus, comprising:
an electrolyte, wherein the electrolyte comprises ethylene carbonate, propylene carbonate, a dinitrile compound and a trinitrile compound; and based on a total weight of the electrolyte, a percentage of the ethylene carbonate is x %, a percentage of the propylene carbonate is y %, a percentage of the dinitrile compound is a % and a percentage of the trinitrile compound is b %, and 0.14≤x/y<1, a/b≥1, 10≤x+y≤40; and
a positive electrode, wherein the positive electrode comprises a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, the positive electrode active material layer comprises a positive electrode active material, and under an X-ray diffraction (XRD) test, a peak intensity of plane 003 of the positive electrode active material layer is I 003 , a peak intensity of plane 104 of the positive electrode active material layer is I 104 , and a ratio n of I 003 to I 104 satisfies 5≤n≤25 and 0.25≤x/n≤4.
2 . The electrochemical apparatus according to claim 1 , wherein the dinitrile compound comprises at least one of a first dinitrile compound or a second dinitrile compound,
wherein the first dinitrile compound comprises at least one of the following formula I-1 to formula I-7:
the second dinitrile compound comprises at least one of the following formula I-8 to formula I-12:
the trinitrile compound comprises at least one of a first trinitrile compound or a second trinitrile compound,
wherein the first trinitrile compound comprises at least one of the following formula II-1 to formula II-4:
the second trinitrile compound comprises at least one of the compounds represented by the following formula II-5 or formula II-6:
3 . The electrochemical apparatus according to claim 2 , wherein the electrolyte comprises the first dinitrile compound and the second dinitrile compound, and based on the total weight of the electrolyte, a percentage of the first dinitrile compound is a1% and a percentage of the second dinitrile compound is a2%, wherein a2/a1<1.3.
4 . The electrochemical apparatus according to claim 2 , wherein the electrolyte comprises the first trinitrile compound and the second trinitrile compound, and based on the total weight of the electrolyte, a percentage of the first trinitrile compound is b1% and a percentage of the second trinitrile compound is b2%, wherein 0≤b1−b2≤δ.
5 . The electrochemical apparatus according to claim 1 , wherein the electrolyte further comprises a sultone compound.
6 . The electrochemical apparatus according to claim 5 , wherein the sultone compound comprises at least one of the following formula III-1 to formula III-9:
7 . The electrochemical apparatus according to claim 1 , wherein the electrolyte further comprises a sultone compound, and based on the total weight of the electrolyte, a percentage of the sultone compound is c %, wherein 0.05≤c/(a+b)≤1.
8 . The electrochemical apparatus according to claim 7 , wherein the sultone compound comprises at least one of the following formula III-1 to formula III-9:
9 . The electrochemical apparatus according to claim 1 , wherein the electrolyte further comprises a boron-containing lithium salt, and the boron-containing lithium salt comprises at least one of lithium oxalate borate, lithium difluorooxalate borate, lithium tetrafluoroborate, or lithium borate.
10 . The electrochemical apparatus according to claim 9 , wherein based on the total weight of the electrolyte, a percentage of the boron-containing lithium salt is d %, wherein d/a≤0.5.
11 . The electrochemical apparatus according to claim 1 , wherein the positive electrode active material contains element M, and the element M contains at least one of Zn, Ti, Al, W, Zr, Nb, Y, or Sb.
12 . The electrochemical apparatus according to claim 1 , wherein in differential scanning calorimetry (DSC) analysis, the positive electrode active material layer has an exothermic peak between 240° C. and 270° C.
13 . The electrochemical apparatus according to claim 1 , wherein a thickness of the positive electrode active material layer on one side of the positive electrode current collector ranges from 25 μm to 70 μm.
14 . An electronic apparatus, comprising an electrochemical apparatus, wherein the electrochemical apparatus comprises:
an electrolyte, wherein the electrolyte comprises ethylene carbonate, propylene carbonate, a dinitrile compound and a trinitrile compound; and based on a total weight of the electrolyte, a percentage of the ethylene carbonate is x %, a percentage of the propylene carbonate is y %, a percentage of the dinitrile compound is a % and a percentage of the trinitrile compound is b %, and 0.14≤x/y<1, a/b≥1, 10≤x+y≤40; and
a positive electrode, wherein the positive electrode comprises a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, the positive electrode active material layer comprises a positive electrode active material; and under an X-ray diffraction (XRD) test, a peak intensity of plane 003 of the positive electrode active material layer is I 003 , a peak intensity of plane 104 of the positive electrode active material layer is I 104 , and a ratio n of I 003 to I 104 satisfies 5≤n≤25 and 0.25≤x/n≤4.