Graphite//LiNi0.5Mn1.5O4 cells based on environmentally friendly in-water-made-electrodes.

The performance of graphite//LiNi0.5Mn1.5O4 (LNMO) cells whose both electrodes are made using water-soluble sodium carboxymethyl cellulose (CMC) binder is reported for the first time. The full cell performed outstandingly at 400 cycles in the conventional electrolyte ethylene carbonate: dimethyl carbonate - 1M LiPF6 and the delivered specific energy at the 100th, 200th, 300th and 400th cycle corresponded to 82%, 78%, 73% and 66% of the initial energy value of 259 Wh kg-1 referred to the sum of the two electrode composite weights. The good stability of high-voltage, LNMO-CMC-based electrodes upon long-term cycling is discussed and the results are compared to those of LNMO composite electrodes with polyvinylidene fluoride (PVdF). LNMO-CMC electrodes outperform those with PVdF binder, displaying a capacity retention of 83%, against 62% of the PVdF-based electrodes after 400 cycles at 1C. CMC promotes a more compact and stable electrode surface than PVdF: unwanted interfacial reactions at high-operating voltages are mitigated, and the thickness of the passivation layer on the LNMO surface is reduced, thereby enhancing its cycling stability.