High-energy low-consumption Al-H2O2 semi-fuel cell

Abstract

The invention relates to a high-energy low-consumption Al-H2O2 semi-fuel cell which comprises an ion exchange membrane clamped between an anode part and a cathode part. The cell is characterized in that the ion exchange membrane is an anion-exchange membrane. The anion-exchange membrane can selectively pass through anions, electric charge is conducted through OH- when the cell is discharged, and OH- generated by a cathode can be automatically transferred to an anode, so that the phenomenon that OH- is excessively accumulated in cathode liquor is avoided, decomposition ratios of H2O2 are reduced, use ratios of the H2O2 are effectively increased, the anode is supplemented by OH-, usage amount of NaOH in anode liquor is reduced, additive amount of electrolyte is reduced, specific energy of the cell is improved, cations are blocked from passing, Al<3+> is prevented from being transferred to the cathode, deformation of Al(OH)3 sediment is prevented, cell performances are improved, and service life of the ion exchange membrane is prolonged.

Description

technical field [0001] The invention belongs to the technical field of chemical power sources, in particular to a high-energy and low-consumption Al-H 2 o 2 half fuel cell. Background technique [0002] Al-H 2 o 2 The semi-fuel cell system has high energy density and is especially suitable for long-term discharge. in Al-H 2 o 2 In half fuel cells, due to the H 2 o 2 A direct chemical reaction will occur when the catholyte is in contact with the anode plate. This side reaction will not generate an external current, but it will consume more than 50% of the active material and reduce the output energy of the battery. Anodes are isolated. Al-H 2 o 2 When the battery is discharged, the main chemical reaction equation shown in Table 1 occurs. As the discharge reaction proceeds, the negative charge of the cathode continues to increase as shown in Table 1. figure 2 As shown, since the Nafion cation exchange membrane is selectively permeable to Na + , while preventing th...

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Problems solved by technology

Al-H 2 o 2 When the battery is discharged, the main chemical reaction equation shown in Table 1 occurs. As the discharge reaction proceeds, the negative charge of the cathode continues to increase as shown in Table 1. figure 2 As shown, since the Nafion cation exchange membrane is selectively permeable to Na + , while preventing the penetration of anions, so Na + Transfer from the anolyte to the catholyte to realize the charge conservation of the battery; when the cation exchange membrane is used, there are usually the following three disadvantages: first, due to the H 2 o 2 OH will be continuously generated on the electrode side - ,OH - The continuous accumulation increases the pH value of the solution, and under alkaline conditions, as the pH value increases, the H 2 o 2 Decomposition produces O 2 The rate of will increase significantly, thus leading to H 2 o 2 Greatly reduced utilization

Second, since the cation exchange membrane cannot block the Al in the anode part 3+ Diffusion to the cathode, Al 3+ will react with the OH of the cathode - Form Al(OH) 3 Colloidal precipitation reduces the catalytic performance of the cathode catalyst and affects the normal discharge reaction of the cathode. The formation of precipitation will also greatly reduce the ion conductivity and service life of the ion exchange membrane

Finally, for 6e - For direct oxidation, as shown in Table 1, 2mol Al 3+ Need 8mol Na + To conduct charge, the NaOH concentration in the solution must be Al 3+ More than 4 times of the battery can meet the needs of battery discharge, and the higher material consumption reduces the high specific energy advantage of the battery

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