Improvement of Cycling Stability at 80°C for 4 V-Class Lithium-Ion Batteries and Safety Evaluation

The cycling stability at 80°C for the LiNi1/3Co1/3Mn1/3O2 (LNCMO) electrodes was improved by using a carboxymethyl cellulose (CMC) binder and then Li4Ti5O12 (LTO)-coating on the particle surface. The detailed structural analysis was done for the LTO-coated LNCMO(CMC) electrode after 100 charge-discharge cycles at 80°C by high-energy synchrotron X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS) analyzes. The number of exchanged electrons (NEE) for the nickel ions in the electrode was lower at 100 cycles than at the first cycle and in a good relation with the capacity of the LTO-coated LNCMO(CMC)/SiO cell. The 1.7 Ah LTO-coated LNCMO(CMC)/SiO laminate cells were prepared in order to evaluate their safety, showing a higher safety for the nail penetration test.