Atypical Analysis of a Graphite-Based Anode Prepared Using Aqueous Processes

In order to form a solid electrolyte interphase (SEI) layer using aqueous processes, a graphite anode called MG-AQP was designed by wrapping and crosslinking graphite particles with aqueous composites (AQCs), which contained zwitterionic polymer, zwitterion molecules, and lithium salts. First, MG-AQP was used to fabricate a full lithium-ion battery (LIB) cell with Li[Ni_0.8Mn_0.1Co_0.1]O₂ (NMC811) as the cathode, denoted as LIB-MG-AQP//NMC811, to demonstrate its performance via a 0.5 C-rate break-in and 1 C-rate cycling. Accordingly, this showed that LIB-MG-AQP exhibits outstanding cyclic stability. To evaluate its electrochemical performance, MG-AQP and lithium metal were used to fabricate a half cell named LIBs-MG-AQP. According to the initial cyclic voltammetry curve, almost no surface reaction for forming an SEI layer exists in LIBs-MG-AQP, illustrating its high initial coulombic efficiency of 92% at a 0.5 C-rate break-in. These outstanding results are due to the fact that the AQC has fewer cracks, thus blocking solvent molecules from passing from the electrolyte into the graphite anode. This study provides new insights to optimize graphite anodes via 0.5 C-rate break-in rather than conventional SEI formation to save time and energy.