Unveiling the Fabrication of Rocking-Chair Type 3.2 and 1.2 V Class Cells Using Spinel LiNi0.5Mn1.5O4 as Cathode with Li4Ti5O12

We first report the possibility of using spinel LiNi0.5Mn1.5O4 (LNM) nanofibers as cathode for constructing high (similar to 3.2 V) and low (similar to 1.2 V) voltage rocking-chair type Li-ion cells with spinel Li4Ti5O12 (LTO) by utilizing Li-insertion into tetrahedral (Ni2+/4+) and octahedral (Mn4+/3+) sites of LNM. We also explored the possibility of constructing symmetric cells (LNM/LNM) with a working potential of similar to 1.8 V. Among the three configurations investigated, LNM/LTO (electrochemically prelithiated) is found superior in terms of high rate capability, cyclability, and good capacity retention characteristics. High performance spinel LNM nanofibers are prepared via a scalable electrospinning technique and their Li-insertion properties are evaluated in half-cell assembly. The half-cell studies are used for adjusting the mass balance while fabricating rocking-chair Li-ion cells.