Extending the life of lithium batteries - nano silica sandwich diaphragm
Publish：Sino Energy Corporation Time：2017-01-04
[lithium engineering comprehensive report]
As one of the high specific capacity battery systems, the growth of dendrite and the instability of SEI film have been a major challenge in the research field. At present, a lot of researches have been done to improve the safety of lithium battery from the aspects of electrode material, electrolyte and separator. There are many studies to enhance the safety of the battery by strengthening the diaphragm, and through the use of ceramic coating to improve the strength of the diaphragm is one of the common methods.
But this method still exists some problems: (1) ceramic coating can be in direct contact with the electrode materials of electrochemical reaction; (2) to improve the wettability of ceramic materials for electrolyte, the coating on the diaphragm, the performance of complementary; (3) in the charge discharge process, ceramic materials may be from the diaphragm off.
Recently, the CuiYi team has extended the life of lithium metal batteries by the preparation of nano silica sandwich diaphragm. Compared with the traditional sandwich diaphragm, the diaphragm is characterized in that: (1) nano silica as interlayer, which can prevent the occurrence of adverse reactions; (2) nano silica particles for lithium ion accumulation and electrolyte through adequate space; (3) silica as insulating material, can only react in lithium the metal diaphragm piercing, to prevent the further growth of dendrite. Fig. 1 schematic and SEM diagram of nano silica sandwich membrane
The experiments of nano silica sandwich diaphragm, common diaphragm and nano silicon sandwich diaphragm, PMMA sandwich diaphragm were compared, found that the silica sandwich diaphragm can be more effectively reduce dendrite growth further, improve the safety of lithium metal batteries. Figure 2 (a) the STEM diagram of F and EELS (b) Li (c) Si, (d) O distribution of the silicon dioxide (E) discharge curve of the silica nanoparticles
Fig. 3 (a) comparison of the different blocking inhibition of dendrite penetration. (b) nano silicon dioxide sandwich separator to improve the safety of the battery In summary, this work through the design of nano silica sandwich diaphragm in dendrite into diaphragm effective dendrite growth slowed further, to improve the safety of lithium metal batteries, has a guiding significance for the design of lithium battery. Relevant research results published in the famous Advanced Materials publications (DOI:10.1002/adma.201603987.KaiLiu, Denys Zhuo, Hyun-Wook Lee, Wei Liu, Dingchang Lin, Yingying Lu, and Yi Cui.Extending the Life of Lithium-Based Rechargeable Batteries by Reaction ofLithium Dendrites with a Novel Silica Nanoparticle Sandwiched Separator. Adv.Mater. 2016).
