Extraction of High Performance Cathode Materials for Lithium Ion Batteries by Sodium Alginate

　　The latest report of sodium alginate manufacturers: Sodium alginate can be used to extract high-performance cathode materials for lithium ion batteries. The specific information is as follows.


　　　　　　 Li(NixCoyMnz)O2 ternary material with layered structure has the characteristics of high specific capacity, good structure and thermal stability, and is considered as the most promising cathode material for lithium ion batteries. Especially ni-rich ternary oxide Li(NixCoyMnz)O2 (x ≥ 0.5), which has become a hot research topic in recent years because of its higher specific capacity. However, the mixed cation discharge of Ni and Li leads to poor cycle stability and low rate performance. While controlling the lithiation temperature and the ratio of lithium to excess metal, the traditional method will lead to excess lithium on the surface of the material, thus limiting the diffusion of Li ions and reducing the cycle stability.

　　Professor Yang Dongjiang from Qingdao University and researcher Zhang Tierui from Institute of Physical and Chemical Technology of Chinese Academy of Sciences have prepared Li(NixCoyMnz)O2 Ni-rich multi-layer hollow fiber materials with low cation mixing by using green seaweed fibers as templates. Four molecules of alginic acid α The molecular chain of -L- guluronic acid was cross-linked with Ni, Co and Mn by plasma to obtain isolated "egg box" structure, while β The combination of -L- guluronic acid molecular chain and Li ion can effectively control cation mixing. It is found that the mixed discharge of cations in Li(Ni0.5Co0.2Mn0.3)O2 multi-shell fiber is as low as 0.0485. Compared with the traditional Ni-rich ternary cathode material, Li(NixCoyMnz)O2 Ni-rich multilayer hollow fiber shows excellent electrochemical performance: when x=0.8, the first discharge specific capacity reaches 229.9 mAh g-1 at a current density of 20 mA g-1, and after 300 cycles at a current density of 100 mA g-1, the capacity retention rate is 84.36%. Under the high current density of 2 A g-1, the discharge capacity reached 172.7 mAh g-1. This excellent performance is attributed to the low cation mixing defect and the conductive network of multilayer hollow fiber. Related papers were published online in adv.sci. (doi: 10.1002/advs.201600262).