269
Preparation and Stability Research of Ago As Cathode Material
Preparation and Stability Research of Ago As Cathode Material
Tuesday, October 13, 2015
West Hall 1 (Phoenix Convention Center)
Silver-zinc battery (AgO/Zn) is regarded as an energy storage system with advantages of high energy density, high power density and superior rate capability when compared with Ni-MH and lithium battery systems. Due to its relatively high cost, AgO/Zn batteries are widely employed in the field of underwater devices, fish torpedo and aerial/space applications. nanoscaled AgO with high purity was synthesized by a chemical precipitation method, and found this method suited to industrialized production. the electrode offers a discharge voltage plateaus of 1.3-1.58V, a discharge capacity of above 393 mAh·g−1 at 8 C rate ,and an exciting specific power density much higher than the current level for existing secondary batteries and super capacitors.
As a cathode material for AgO/Zn battery, AgO suffers severely from its poor thermal stability. During long-term storage, AgO decomposes and generates Ag2O and Ag, which in return fasten the decomposition process of AgO. As a result, decomposition issue for AgO even occurs at room temperature. To the best of our knowledge, there is few study regarded to the thermal stability of AgO and no mature fabrication process for AgO has been reported. Na2SiO3, well-know inhibiter, is widely used in alkaline Zn-MnO2 battery to improve stability of the battery. However, there is no systematic investigation of using Na2SiO3 as stability agent in AgO/Zn system. Herein, the effects of Na2SiO3 on the thermal stability and electrochemical performance of AgO are elucidated.
Through aging treatments, it is concluded that with the introduction of Na2SiO3, the decomposition degree of AgO at room temperature has been reduced to some extent. However, the decomposition temperature of AgO remains unchanged. On the other hand, electrochemical performance of AgO/Zn battery is degraded with addition of Na2SiO3 in the cathode material due to the poor conductivity of Na2SiO3. The results showed that 10 min later after the injection of KOH electrolyte into the cell model, Na2SiO3 mainly influences discharge voltage at early stage when discharging the cell at 4 C with voltage cut-off at 1.0 V. The discharge voltage drop at early stage increases significantly with increasing the amount of Na2SiO3. The open circuit voltage of the AgO with 2wt% Na2SiO3 as cathode was 1.6 V and the voltage suddenly dropped to 1.18 V after the current was applied. The discharge voltage for the AgO with 10.7wt% Na2SiO3 as cathode drastically dropped to 0.2 V under the same test condition. Interestingly, the discharge voltage turned out to be almost identical after discharging for 20 s for all the cells with different weight ratio of AgO as cathodes. These results indicates that the introduction of Na2SiO3 in the AgO cathode mainly influence solution equilibrium.
As a cathode material for AgO/Zn battery, AgO suffers severely from its poor thermal stability. During long-term storage, AgO decomposes and generates Ag2O and Ag, which in return fasten the decomposition process of AgO. As a result, decomposition issue for AgO even occurs at room temperature. To the best of our knowledge, there is few study regarded to the thermal stability of AgO and no mature fabrication process for AgO has been reported. Na2SiO3, well-know inhibiter, is widely used in alkaline Zn-MnO2 battery to improve stability of the battery. However, there is no systematic investigation of using Na2SiO3 as stability agent in AgO/Zn system. Herein, the effects of Na2SiO3 on the thermal stability and electrochemical performance of AgO are elucidated.
Through aging treatments, it is concluded that with the introduction of Na2SiO3, the decomposition degree of AgO at room temperature has been reduced to some extent. However, the decomposition temperature of AgO remains unchanged. On the other hand, electrochemical performance of AgO/Zn battery is degraded with addition of Na2SiO3 in the cathode material due to the poor conductivity of Na2SiO3. The results showed that 10 min later after the injection of KOH electrolyte into the cell model, Na2SiO3 mainly influences discharge voltage at early stage when discharging the cell at 4 C with voltage cut-off at 1.0 V. The discharge voltage drop at early stage increases significantly with increasing the amount of Na2SiO3. The open circuit voltage of the AgO with 2wt% Na2SiO3 as cathode was 1.6 V and the voltage suddenly dropped to 1.18 V after the current was applied. The discharge voltage for the AgO with 10.7wt% Na2SiO3 as cathode drastically dropped to 0.2 V under the same test condition. Interestingly, the discharge voltage turned out to be almost identical after discharging for 20 s for all the cells with different weight ratio of AgO as cathodes. These results indicates that the introduction of Na2SiO3 in the AgO cathode mainly influence solution equilibrium.