Enhancing Orbital Interaction in Spinel LiNi0.5Mn1.5O4 Cathode for High‐Voltage and High‐Rate Li‐Ion Batteries

Abstract High voltage cobalt‐free spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) is well organized as a high‐power cathode material for lithium (Li)‐ion batteries, however, the weak interaction between the 3 d orbital of the transition metal (TM) ions and the 2 p orbital of oxygen (O) leads to the instability of crystal structural, hindering the long‐term stable cycling of LNMO cathode especially at high temperatures. Here, a design strategy of orbital interaction is initiated to strengthen TM 3 d ‐O 2 p framework in P‐doped LNMO (P‐LNMO) by choosing phytic acid as P dopant, which can realize more uniform doping compared to regular phosphate. The results show that the enhancement of TM 3 d ‐O 2 p orbital interaction in P‐LNMO can suppress the Jahn–Teller effect and subsequent dissolution of Mn, as well as lowers the energy barrier for Li ion insertion/extraction kinetics. As a result, superior electrochemical performances including high discharge capacity, stable cycling behavior and enhanced rate capability of P‐LNMO are obtained. Significantly, the P‐LNMO pouch cell shows great cycling stability with 97.4% capacity retention after 100 cycles.