| CPC H01M 10/0569 (2013.01) [H01M 10/0525 (2013.01); H01M 2220/30 (2013.01); H01M 2300/0034 (2013.01)] | 16 Claims | 

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               1. An electrochemical apparatus, comprising: 
              an electrolyte, a positive electrode and a negative electrode; 
                wherein, the negative electrode comprises a negative active material layer, and the negative active material layer comprises a negative active material; 
                the electrolyte comprises fluoroethylene carbonate; and 
                0.5<Rct/Rcp<1.5, and both Rct and Rcp are less than 35 milliohms, 
                wherein Rot represents a charge transfer resistance under 50% state of charge at 25 degrees Celsius, and Rcp represents a concentration polarization resistance in the 50% state of charge at 25 degrees Celsius; and 
                0.005≤A/B≤0.1, 
                wherein a mass of the fluoroethylene carbonate corresponding to 1 g of the negative active material is A g, and a specific surface area of the negative active material is B m2/g, 
                wherein the electrolyte contains a compound of formula I: 
              ![]() wherein R11 is selected from hydrogen, a hydroxy group, a C1-20 alkyl group, a C1-20 alkoxy group, a C2-20 alkenyl group, a C6-30 aryl group, or a C6-30 aryloxy group; 
                R12 is selected from hydrogen, a C1-20 alkyl group, a C2-20 alkenyl group, or a C6-30 aryl group; 
                wherein a mass of the compound of formula I corresponding to 1 g of the negative active material is X g, and the value of X ranges from 0.035 to 0.39, and 
                wherein 0.67≤X/A≤20. 
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