Brief analysis of the working principle of Ni-MH battery

The nickel-hydrogen battery is composed of nickel hydroxide positive electrode, hydrogen storage alloy negative electrode, diaphragm paper, electrolyte, steel shell, upper cover, sealing ring and so on. In a cylindrical battery, the positive and negative electrodes are respectively wrapped with separator paper and sealed in a steel box. In a prismatic battery, the positive and negative electrodes are separated by separator paper, folded into a layer and sealed in a steel case. The nickel-metal hydride battery principle is composed of: cathode material: hydrogen storage alloy powder cathode material: Ni(OH)2 cell voltage: 1.2v cycle life 500-1000 times nickel-metal hydride battery electrolyte is important to use KOH as the electrolyte ( The electrolyte is 7moL/LKOH+15g/LLiOH) Ni-MH battery charging positive reaction: Ni(OH)2+OH-→NiOOH+H2O+e-Negative reaction: M+water+e-→MH+ Oh total reaction: M+Ni (OH)2→MH+NiOOH When the Ni-MH battery is discharged, the positive electrode: NiOOH+H2O+e-→Ni(OH)2+OH-Negative: MH+OH-M+H2O+e-Total reaction: MH+NiOOH→ M+Ni(OH)2 where M is a hydrogen storage alloy, and MH is a hydrogen storage alloy that adsorbs hydrogen atoms. The most commonly used hydrogen storage alloy is LaNi5. Ni-MH battery over-discharge: Nickel hydroxide electrode (positive) 2H2O+2e->H2+2OH-hydrogen absorption electrode (negative) H2+20H-2e→2H20 When the battery is over-discharged, the net result of the total reaction is zero. The hydrogen present on the positive electrode recombines on the negative electrode, which also keeps the battery system stable. Ni-MH battery overcharge: nickel hydroxide electrode (positive electrode) oh-4e->2H2O+O2 hydrogen absorption electrode (negative electrode) H2O+O2+4e>4OH nickel hydroxide electrode is filled with oxygen that appears after being diffused on the negative electrode and re-synthesized water. It not only makes the internal pressure of the battery constant, but also makes the electro-hydraulic concentration change little. The nickel-hydrogen battery is composed of nickel hydroxide positive electrode, hydrogen storage alloy negative electrode, diaphragm paper, electrolyte, steel shell, upper cover, sealing ring and so on. In a cylindrical battery, the positive and negative electrodes are respectively wrapped with separator paper and sealed in a steel box. In a prismatic battery, the positive and negative electrodes are separated by separator paper, folded into a layer and sealed in a steel case. The application of metal hydride nickel battery The application of nickel hydrogen battery: civil communication power supply, various portable equipment power supply, power tool power supply, power supply, etc. Small green power supply replaces nickel-cadmium batteries. The oxygen that appears after the nickel hydroxide electrode is full diffuses on the negative electrode and re-synthesizes water. It not only makes the internal pressure of the battery constant, but also makes the electro-hydraulic concentration change little. The reaction of the positive and negative electrodes of MH/Ni batteries is a solid phase transition mechanism, and no additional electrolyte components will appear or consume. Therefore, the positive and negative electrodes of the battery have high stability, and can be sealed and maintenance-free. Ni-MH batteries generally adopt super-negative capacity configuration. When the battery is overcharged, the oxygen released from the positive electrode can be reduced to water on the surface of the metal hydride electrode. When the electrode is covered, the hydrogen precipitated from the positive electrode can be absorbed by the metal hydride electrode, so that the battery has a good overcharge resistance. When oxygen precipitates diffuse from the positive electrode to the negative electrode and react with hydrogen, not only part of the hydrogen in the negative electrode is consumed, which affects the electrode potential of the negative electrode, but also the release of heat will cause a significant increase in the internal temperature of the battery, thereby accelerating the electrode reaction. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete it.