ELECTROCHEMICAL CELL AND METHOD OF MAKING THE SAME
A secondary cell comprising a positive cathode electrode of capacity P (mAh) in communication with a liquid or gel electrolyte; an negative anode electrode of capacity N (mAh) in communication with the electrolyte; and a separator permeable to at least one mobile species which is redox-active at least one of the anode and the cathode; designed and constructed such that the anode capacity N is smaller than that of the cathode capacity P, hence N/P<0.9.
1 . A rechargeable electrochemical cell, comprising:
a non-aqueous electrolyte;
a negative electrode in direct physical contact with said non-aqueous electrolyte, said negative electrode having a capacity N mAh;
a positive electrode in direct physical contact with said non-aqueous electrolyte, said positive electrode having a capacity P mAh,;
wherein said capacity N mAh of said negative electrode is strictly less than said capacity P mAh of said positive electrode;
wherein said rechargeable electrochemical cell is configured to charge to greater than or equal to 4.3 V.
2 . The rechargeable electrochemical cell of claim 1 , wherein a ratio of reversible capacity between said negative electrode and said positive electrode is such that Q(negative electrode)/Q(positive electrode)<0.9 and Q(negative electrode)/Q(positive electrode)>0.
3 . The rechargeable electrochemical cell of claim 1 , wherein the electrochemical cell is configured for an average discharge potential of greater than or equal to 3.80 V during a 0.2 C-rate discharge.
4 . The rechargeable electrochemical cell of claim 1 , wherein said capacity N mAh of said negative electrode is strictly less than said capacity P mAh of said positive electrode, and is also greater than zero.
5 . The rechargeable electrochemical cell of claim 1 , configured to charge and discharge with >99.35% Coulombic efficiency.
6 . The rechargeable electrochemical cell of claim 1 , configured to provide at least 80% of initial capacity for greater than 30 charging and discharging cycles.
7 . The rechargeable electrochemical cell of claim 1 , wherein said negative electrode is configured to provide >1000 mAh/cc.
8 . The lithium electrochemical cell of claim 1 , wherein said negative electrode comprises less than or equal to 3 mAh/cm2 of electro-active material in the discharged state.
9 . The lithium electrochemical cell of claim 1 , wherein said negative electrode comprises greater than or equal to 3 mAh/cm2 of electro-active material in the charged state.
10 . The rechargeable electrochemical cell of claim 1 , wherein said non-aqueous electrolyte comprises at least one active cation selected from the group consisting of Mg ion, Al ion, Ca ion, Sr ion, Ba ion, Li ion, Na ion, K ion, Rb ion, Cs ion, and onium.
11 . The rechargeable electrochemical cell of claim 1 , wherein said non-aqueous electrolyte salt comprises an anion at least in part from one or more of the following anions: bis(perfluoroalkylsulfonyl)imides, bis(fluorosulfonyl)imide, bis(trifluoromethanesulfonyl)imide, bis(perfluoroethylsulfonyl)imide, Dicyanamide, Tricyanomethide, tetracyanoborate, 2,2,2,-trifluoro-N-(trifluoromethylsulfonyl)acetamide, tetrafluoroborate, hexafluorophosphate, triflate, bis(oxalato)borate, difluoro(oxalato)borate, perchlorate, hexafluoroarsenate, Hexafluoroantimonate, Perfluorobutylsulfonate, Tris(trifluoromethanesulfonyl)methide, trifluoroacetate, heptafluorobutanoate, thiocyanate, or triflinate.
12 . The rechargeable electrochemical cell of claim 1 , wherein the one or more salts comprise at least three elements and include two or more of the following: boron, phosphorous, fluorine, carbon, nitrogen, sulfur, and oxygen.
13 . The rechargeable electrochemical cell of claim 1 , comprising an electrolyte component including in part a polymer, a liquid, a gel, or solid electrolyte.
14 . The rechargeable electrochemical cell of claim 1 , comprising an electronically insulating separator configured to separate said negative electrode and said positive electrode.
15 . The rechargeable electrochemical cell of claim 1 , wherein said non-aqueous electrolyte comprises a salt, or combination of salts in a concentration in the range of 0.5 M to saturated concentration.
16 . The rechargeable electrochemical cell of claim 1 , wherein at least one of said negative electrode or positive electrode comprises at least one metal selected from the group consisting of Mg, Li, or Na, an alloy thereof, or an intermetallic compound thereof, which is configured to plate onto a negative electrode current collector during charging.
17 . The rechargeable electrochemical cell of claim 1 , wherein at least one of said negative electrode or positive electrode comprises a material configured to undergo an insertion reaction, an alloying, an intercalation, a disproportionation, a conversion reaction, or a combination thereof.
18 . The rechargeable electrochemical cell of claim 1 , wherein a pressure perpendicular to the interface of the positive and negative electrodes is greater than 0.06 MPa.
19 . A rechargeable electrochemical cell of claim 1 wherein the negative electrode is not comprised at least in part of electrochemically active titanium oxide compound.
20 . A rechargeable electrochemical cell of claim 1 wherein the non-aqueous electrolyte is a fluid electrolyte and does not comprise a molten salt.
21 . The rechargeable electrochemical cell of claim 1 , wherein a ratio defined by said capacity of said negative electrode divided by said capacity of said positive electrode is in a range selected from the ranges of zero to 0.10, zero to 0.20, zero to 0.30, zero to 0.40, zero to 0.50, zero to 0.60, zero to 0.70, zero to 0.80, and zero to 0.90.
22 . The rechargeable electrochemical cell of claim 1 , wherein a ratio defined by said capacity of said negative electrode divided by said capacity of said positive electrode is in a range selected from the ranges of 0.05 to 0.10, 0.05 to 0.20, 0.05 to 0.30, 0.05 to 0.40, 0.05 to 0.50, 0.05 to 0.60, 0.05 to 0.70, 0.05 to 0.80, and 0.05 to 0.90.
23 . A battery comprising more than one of the rechargeable electrochemical cells of claim 1 configured in combination of series and parallel electrical connection to provide electrical power to a device.