Water-Soluble Sericin Protein Enabling Stable Solid–Electrolyte Interphase for Fast Charging High Voltage Battery Electrode

5 years ago

Water-Soluble Sericin Protein Enabling Stable Solid–Electrolyte Interphase for Fast Charging High Voltage Battery Electrode

Xiaodong Chen, Zhong Chen, Xinran Zhou, Shaowu Pan, Jiyang Deng, Oleksandr I. Malyi, Wenlong Li, Yurong Cai, Yuxin Tang, Yanyan Zhang, Jiaqi Wei

Spinel LiNi0.5Mn1.5O4 (LNMO) is the most promising cathode material for achieving high energy density lithium-ion batteries attributed to its high operating voltage (≈4.75 V). However, at such high voltage, the commonly used battery electrolyte is suffered from severe oxidation, forming unstable solid–electrolyte interphase (SEI) layers. This would induce capacity fading, self-discharge, as well as inferior rate capabilities for the electrode during cycling. This work first time discovers that the electrolyte oxidation is effectively negated by introducing an electrochemically stable silk sericin protein, which is capable to stabilize the SEI layer and suppress the self-discharge behavior for LNMO. In addition, robust mechanical support of sericin coating maintains the structural integrity during the fast charging/discharging process. Benefited from these merits, the sericin-based LNMO electrode possesses a much lower Li-ion diffusion energy barrier (26.1 kJ mol−1) for than that of polyvinylidene fluoride-based LNMO electrode (37.5 kJ mol−1), delivering a remarkable high-rate performance. This work heralds a new paradigm for manipulating interfacial chemistry of electrode to solve the key obstacle for LNMO commercialization, opening a powerful avenue for unlocking the current challenges for a wide family of high operating voltage cathode materials (>4.5 V) toward practical applications. The electrolyte oxidation issue for high-voltage LiNi0.5Mn1.5O4 (LNMO) cathodes is effectively negated by introducing an electrochemically stable silk sericin protein, which is capable of stabilizing the solid–electrolyte interphase layer and suppressing self-discharge behavior for LNMO. Benefiting from this, a sericin-based LNMO electrode processes a low Li-ion diffusion energy barrier, delivering a remarkable high-rate performance.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adma.201701828