Pre-pulverizing Ni-rich layered oxide cathodes via “liquid explosive” infiltration toward highly endurable 4.5 V lithium batteries

Abstract

The mechanical strain derived from anisotropic lattice distortion would lead to the spread of microcracks in LiNixMnyCo1-x-yO2 (NMC) secondary particles and therefore the rapid capacity deterioration. Herein, we propose a ‘liquid explosion’ strategy to pre-pulverize the agglomerated secondary particle system of LiNi0.8Mn0.1Co0.1O2 (NMC811) massively into an unusual primary particle system via the infiltration of P3N3Cl6 (PNCL) melt and its following gasification. This primary particle system avoids the prevalence of microcracks and degradation of electric contact in electrode network. The high dispersity of particles enables the more homogenous and compact electrode network, which is well preserved even after long-term cycling. The residual PNCL releases N, Cl and P elements, which are implanted into an ultrathin cathode electrolyte interphase (CEI) and lithiated into conductive Li3N, LiCl and LixPOyFz components. The modified Li-NMC cells exhibit the ultralong cycling life (at least 1100 cycles at 1 C) with very small capacity fading rate (0.043% per cycle) even under the protocol of high cut-off voltage (4.5 V). This endurable discrete-particle-type electrode network also endows the high-loading cathode with excellent capacity retention even under the configuration of pouch cell. The concept of ‘liquid explosive’ provides a scalable solution to high-performance NMC based materials for practical battery application.