Structural and Electrochemical Aspects of Ni-Rich Electrodes for Lithium-Ion Batteries

摘要

The most promising cathode materials for lithium ion batteries (LIBs) are the lithium intercalation transition metal oxides of layered structure (R-3m), Li[NixCoyMnz]O2 (x+y+z=1) (NCM). NCM materials can exhibit specific capacity > 200 mAhg-1 at Ni-content of ≥80 %. They can also demonstrate high rate capability and may reach relatively low costs (1). However, these materials have disadvantages like low electronic and ionic conductivities and structural instability; their capacity also decays fast upon cycling (2). In this presentation, we summarize our recent studies of Li[NixCoyMnz]O2 for electrodes of LIBs. We focus on a family of Ni-rich (x=0.5 – 0.8) materials with various content of Co and Mn. The main questions studied were lattice doping with Al3+, Zr4+ and Mo6+ cations of the above materials in relation to the electrode behavior, structural stability, electronic properties, and thermal reactions with battery solutions. We elucidated also possible structural transformations of these electrode materials upon Li-intercalation/deintercalation.