Optimizing the Lithium Phosphorus Oxynitride Protective Layer Thickness on Low‐Grade Composite Si‐Based Anodes for Lithium‐Ion Batteries

Abstract

Composite materials containing Si as a component, are growing importance in the field of Li‐ion battery due to their extremely high theoretical capacity (3500 mAh g−1 at room temperature). However, the capacity of Si anode material decays dramatically because of serious volume variation during lithiation and delithiation process, which lead to deformation of Si electrode and resulted in poor cycle performance. In the present work, we have reported improved performance of modified Si electrode as an anode in Li‐ion battery. Si obtained from kerf‐loss slurry have been alloyed with Ni nanoparticles to improve its conductivity. A mechanistic study of the deposition of LiPON with respect to deposition pressure also presented. It is seen that LiPON layer serves as a protective layer with high ionic conductivity (1.38×10−6 S cm−1) to improve the electrochemical activity of Si−Ni electrode. The optimal 1st charge capacity of LiPON modified‐ Si−Ni composite was 915 mAh g−1 at a current density of 50 mA g−1 in a potential window of 1.2 V to 0.005 V. The charge capacity retained 56.2% of the initial cycle after 90th cycling measurement.

Matchmaker of Marriage between a Li Metal Anode and NASICON-Structured Solid-State Electrolyte: Plastic Crystal Electrolyte and Three-Dimensional Host Structure

“…1−5 Li metal anodes are needed to increase energy density. 6,7 The flammable nature of liquid electrolytes leads to safety problems for Li metal batteries. 6,8−11 Hence, nonflammable solid-state electrolytes were developed to replace liquid electrolytes.…”

“…Li-ion batteries have been applied in various fields since they were first commercialized in the 1990s. The energy density of Li-ion batteries has reached 250 W h kg –1 recently. − Li metal anodes are needed to increase energy density. , The flammable nature of liquid electrolytes leads to safety problems for Li metal batteries. ,− Hence, nonflammable solid-state electrolytes were developed to replace liquid electrolytes . Air-stable Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) with a sodium superionic conductor (NASICON) structure has been intensively studied in recent years. − …”

Interface Between Solid-State Electrolytes and Li-Metal Anodes: Issues, Materials, and Processing Routes

“…Among all types of energy storage devices, the Li-ion batteries (LIBs), which are first commercialized in the early 1990s, have been intensively studied due to their outstanding energy density and life span compared with lead-acid batteries. − Recently, the energy density of Li-ion batteries has reached 200 Wh kg –1 . − To reach an even higher energy density, Li-metal anode is introduced into LIBs due to its high theoretical capacity (3860 mAh g –1 ) and negative electrochemical potential (−3.04 V vs standard hydrogen electrode). − The next-generation Li–S, and Li–O 2 batteries also need Li-metal anodes. − However, interfacial issues, such as dead Li, interfacial side reaction, and dendrites, restrict the practical application of Li metal anodes. ,,,− More seriously, the flammable nature of liquid electrolytes increases the possibility of the fire and explosion …”