Research on the application of high-energy density lithium batteries

The application research of high energy density lithium battery analyzes the energy storage capacity, durability, cost, etc. of the battery data. At present, the most advanced high-energy density lithium battery uses layered lithium transition metal oxide LiMo2 (Mu003dNi, Co and Mn or Al) as cathode activity data (≈150−200mAhg-1 effective discharge capacity) 1−4, graphite (theoretical The specific capacity is 372mAhg-1) as anode activity data. Adding part of silicon (about Li15si4, 3579mAhGSI−1) to the negative electrode has proved to be an effective strategy to further increase the specific energy. For example, Yim et al. used graphite and silicon powder (5%wt%) composite data to prepare and test polyvinylimide adhesive anodes. According to the author, after 350 cycles, the most functional electrode has a specific capacity of 514mAhg-1, which is 1.6 times that of a commercial graphite anode. However, ending the safe cycle of high-content and high-load silicon anodes is very challenging. The most serious defects of silicon used as anode activity data are: (I) high irreversibility, especially in the first two cycles, such as side reactions with electrolyte; (II) and lithium undergoes a large change in volume after alloying, resulting in Particle cracking and anode self-pulverization. Note that all these reverse effects will not only cause a large amount of impedance accumulation during battery operation, but also cause the consumption of cathode lithium. In addition, studies have shown that the contact loss of conductive carbon black/binder network and/or silicon particles in the collector will accelerate the degradation of capacity. In recent years, new and/or improved electrolytes, additives and polymer binders have been tested to overcome important problems with silicon anodes. 11, 13, 15-17 In addition, the focus is to prepare high-quality silicon-based redox activity data. From the perspective of these studies, only a part of it is considered here, especially the Si and SiOx data and their composite data, especially nanocarbon, which has prospects in future energy storage applications. For example, 18-21, Breitung et al. produced a composite material of silicon particles and carbon nanofibers. After hundreds of cycles, its capacity was approximately twice that of the original silicon particle electrode. Hu Jintao and others. The results show that in silicon storage, the capacity retention rate of carbon-coated silicon particles can be improved after glucose is hydrothermally carbonized. Inspired by these studies, the purpose of this study is to use polymer pre-coated silicon particles to prepare nano-Si/C composites with a core-shell structure. Electron microscopy, X-ray diffraction and Raman spectroscopy were used to characterize the carbonized powder samples at 700~900℃. In addition, the in-situ pressure method, differential electrochemical mass spectrometry and acoustic emission method were used to analyze the volume expansion, gas permeability and mechanical deformation/degradation of the actual electrode by the silicon/carbon composite particles. 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.