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

Abstract

Spinel LiNi Mn O (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 ) for than that of polyvinylidene fluoride-based LNMO electrode (37.5 kJ mol ), 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.

Approaching the Lithiation Limit of MoS2 While Maintaining Its Layered Crystalline Structure to Improve Lithium Storage

“…[20] Severe issues such as material pulverization and repeated solid-electrolyte interphase (SEI) formation would occur, finally causing rapid capacity decay. [22] This is supported by energy-dispersive Xray spectroscopy (EDX;Supporting Information, Figure S14) and X-ray photoelectron spectroscopy (XPS;S upporting Information, Figure S15) analysis,w hich reveal that the composition of the SEI continues to change when the electrode is cycled in 3.0-0.5 V, while the SEI layers keep relatively constant for electrodes cycled in 3.0-1.0 Vand 3.0-0.6 V. Thet hicker SEI could hinder charge transfer and consequently lead to large interfacial resistance, [23] as shown by the impedance study (Supporting Information, Figure S16). Thesurface of MoS 2 particles cycled in 3.0-1.0 Vand 3.0-0.6 Vremain smooth even after 200 cycles,suggesting the formation of thin and stable SEI.…”

“…However, alarge amount of floccule appears on the surface of MoS 2 particles after cycling in 3.0-0.5 Vf or 200 cycles,w hich is indicative of successive SEI formation. [22] This is supported by energy-dispersive Xray spectroscopy (EDX;Supporting Information, Figure S14) and X-ray photoelectron spectroscopy (XPS;S upporting Information, Figure S15) analysis,w hich reveal that the composition of the SEI continues to change when the electrode is cycled in 3.0-0.5 V, while the SEI layers keep relatively constant for electrodes cycled in 3.0-1.0 Vand 3.0-0.6 V. Thet hicker SEI could hinder charge transfer and consequently lead to large interfacial resistance, [23] as shown by the impedance study (Supporting Information , Figure S16). Thea bove results clearly prove our conclusion that the structural degradation of MoS 2 ,w hich induces large volume changes,i sr esponsible for capacity fading when cycling between 3.0-0.5 V.…”

A Flexible, Binder‐Free Graphene Oxide/Copper Sulfides Film for High‐Performance Sodium Ion Batteries

“…Furthermore, it is apparent that the constitution of CuS−F is abundant with porous architecture, which could facilitate electrolyte access throughout the multi sandwich‐like structure and the transfer of Na ion during cycling. To an extent, the rational electrode‐structure design, which may maximize both ionic and electronic conductivity in the electrode with a short diffusion length, can enhance the electrochemical performance effectively . As depicted in high‐magnification SEM image (Figure S2(a)), electrical conductor SP nanoparticles were mixed well with CuS powder, leading to an adequate electrical conductivity.…”

Fast‐Charging and High Volumetric Capacity Anode Based on Co3O4/CuO@TiO2 Composites for Lithium‐Ion Batteries

“…Therefore, many researchers have investigated alternative anodic materials to replace graphite . Among them, TiO 2 has attracted considerable interest as an anodic material for next‐generation LIBs owing to its relatively high lithiation potential (≈1.7 V vs. Li/Li + ), which enables safer operation during fast charging . In addition, TiO 2 undergoes an extremely small volume expansion (≈3 %) during the charge/discharge cycle, leading to good cycling stability and rate capability.…”

“…[9][10][11] Amongt hem,T iO 2 has attracted consider-able interest as an anodic materialf or next-generation LIBs owingt oi ts relatively high lithiation potential ( % 1.7 Vv s. Li/ Li + ), which enables safer operation during fast charging. [12][13][14] In addition, TiO 2 undergoes an extremely small volume expansion ( % 3%)d uring the charge/discharge cycle, leadingt o good cycling stabilitya nd rate capability.I ns piteo ft hese advantageouss tructuralp roperties, their low gravimetric capacity (170 mA h À1 g À1 )a nd low electronic and ionic transportk inetics continued to remain ag reat challenge. [15][16][17] Thus, variouss trategies to improve the overall electrochemical properties have been reported; for example, introducing foreigna ctivem aterials into TiO 2 using coating or ion-doping methods.…”