镁锰电池电压滞后机理及调控研究

Voltage delay phenomenon appears in the discharge process of Magnesium- Manganese dioxide dry cell, which limits its application. In situ measurement approaches in the programe such as Ellipsometric and Fourier tansform infrared spectroscopy(FT-IR) shall be developed to test the interface film of magnesium electrode and electrolyte. The component and structure of the corrosion passivation film shall be characterized by some related means such as X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD) and scanning electron microscopy(SEM). The relation between corrosion, anticorrosion and voltage delay will be measured and analyzed. Voltage delay control will come true when the cathode material suface film could be kept to be the state of the passivation and discharge by adjusting component of electrolyte solution and magnesium-alloy material,combining pulse discharge technique. These results including voltage delay mechanism and corrosion of magnesium electrode are significant for the development and application of magnesium primary batteries.

镁锰干电池在放电过程产生"电压滞后现象"导致其应用受限。本项目提出通过现场电化学椭圆法与红外光谱法（FT-IR）原位测量镁电极-电解质界面膜层，采用X射线光电子能谱（XPS）、X射线衍射（XRD）、扫描电镜（SEM）等方法表征腐蚀钝化膜的成分与结构，探索镁电池电压滞后与腐蚀-缓蚀过程的关系；同时通过电解液和负极材料组成的调节并结合脉冲放电技术，使电极材料的表面膜处于钝化又能放电的状态，进而实现电压滞后可调可控。镁电池电压滞后机理与镁电极腐蚀等问题的基础性研究结果对镁电池的发展与应用意义重大。

镁锰电池（Mg-MnO2）具有电压高、存储时间长等特点，但放电过程中产生的“电压滞后现象”使其应用受限。本项目采用线性电位伏安法（LSV）、电化学阻抗谱（EIS）、扫描电镜（SEM）、X射线能谱（EDX）、显微红外光谱（microFT-IR）、X射线衍射（XRD）以及X射线光电子能谱（XPS）等多种电化学研究方法、分析测试方法和现场微区电化学测试技术(SKP、SVET)详细研究了镁合金表面钝化膜形成、扩张、溶解、修复过程，揭示了镁锰电池电压滞后机理，通过电解液复配和电流脉冲技术实现了镁锰电池电压滞后的可调可控。研究结果表明复合电解液（Mg2+、NO3-、SO42-、ClO4-）并与添加剂（F-、PO43-、HCO3-）的协同作用可将镁锰电池的电压滞后时间缩短至0.1 s或电压降仅0.1 V，且双脉冲电流亦可使电压滞后时间降到0.1 s，基本满足镁锰电池的使用要求。研究成果对开发镁锰电池新技术提供了科学理论基础。