Ambient-Air Stable Lithiated Anode for Rechargeable Li-Ion Batteries with High Energy Density

Abstract

An important requirement of battery anodes is the processing step involving the formation of the solid electrolyte interphase (SEI) in the initial cycle, which consumes a significant portion of active lithium ions. This step is more critical in nanostructured anodes with high specific capacity, such as Si and Sn, due to their high surface area and large volume change. Prelithiation presents a viable approach to address such loss. However, the stability of prelithiation reagents is a big issue due to their low potential and high chemical reactivity toward O and moisture. Very limited amount of prelithiation agents survive in ambient air. In this research, we describe the development of a trilayer structure of active material/polymer/lithium anode, which is stable in ambient air (10-30% relative humidity) for a period that is sufficient to manufacture anode materials. The polymer layer protects lithium against O and moisture, and it is stable in coating active materials. The polymer layer is gradually dissolved in the battery electrolyte, and active materials contact with lithium to form lithiated anode. This trilayer-structure not only renders electrodes stable in ambient air but also leads to uniform lithiation. Moreover, the degree of prelithiation could vary from compensating SEI to fully lithiated anode. With this strategy, we have achieved high initial Coulombic efficiency of 99.7% in graphite anodes, and over 100% in silicon nanoparticles anodes. The cycling performance of lithiated anodes is comparable or better than those not lithiated. We also demonstrate a LiTiO/lithiated graphite cell with stable cycling performance. The trilayer structure represents a new prelithiation method to enhance performance of Li-ion batteries.

Challenges and Recent Progress in the Development of Si Anodes for Lithium‐Ion Battery

“…c) Reproduced with permission. [56] Copyright 2016, American Chemical Society. d) Reproduced with permission.…”

“…As illustrated in Figure 5c, lithium is deposited on a Cu foil, and then lithium is coated with a protective polymer layer (polymethyl methacrylate, PMMA) to make it ambient-air-stable. [56] Then, the anode materials, deposited on the top of the polymer layer, can be integrated with electrolyte and conventional cathode materials to make up a real battery. As the polymer coating layer dissolves in the electrolyte, the anode materials contact lithium directly.…”

Challenges of Spinel Li4Ti5O12 for Lithium‐Ion Battery Industrial Applications

“…Reproduced with permission. [140] b) The electrons transfer path on the surface of Ag composed Li 4 Ti 5 O 12 particle.…”

New perspective to understand the effect of electrochemical prelithiation behaviors on silicon monoxide

“…In addition to SEI and irreversible by- products, Li-Si alloy formed aer prelithiated Si was readily demonstrated by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and XRD. 19,24 Analogically, the ICE would be increased from 73.6% to 94.9% via a circuit short with Li metal foil and carbon coated SiO x in the presence of an optimized external resistance. As the shorting time increasing, the progressive reactions between Li and SiO x would form Li-Si alloy.…”