Binder-Free LiNi_0.8Mn_0.1Co_0.1O₂/Multi-Walled Carbon Nanotube Prepared by One-Step Electrophoretic Deposition Method for Efficient Li-Ion-Battery Cathodes

Abstract

A binder-free composite electrode of LiNi0.8Mn0.1Co0.1O2 (NMC811)/multi-walled carbon nanotube (MWCNT) with an extremely high NMC811 mass ratio (91 wt. %) is prepared using an electrophoretic deposition process in a quick time (~3 min). The spherical NMC811 particles are homogenously incorporated in the network created by MWCNTs, with desirable contact between these two components of the composite. The NMC811/MWCNT composite electrode showed a high first discharge capacity of 1.89 mAh/cm2 (163.4 mAh/g) and 1.67 mAh/cm2 after 150 cycles at 0.1 C with 88.3% capacity retention in the charge-discharge process. Compared with the conventional NMC811 electrodes prepared by the electrophoretic process (with carbon black and polyvinylidene fluoride) or doctor-blade strategy, superior electrochemical performance achieved in the binder-free composite NMC811/MWCNT electrode prepared by the electrophoretic process. This improvement is possible because the NMC811/MWCNT composite electrode could allow for a higher surface area and conductivity of the cathode material, a reactive interphase and adjustable available space in the electrode, and a homogenous distribution of the NMC particles in the MWCNT network. This scale-able, simple, binder and NMP-free, time-saving method with controllable growth deposit can be used to fabricate a variety of electrodes in storage systems.