Reinforcing Germanium Electrode with Polymer Matrix Decoration for Long Cycle Life Rechargeable Lithium Ion Batteries

Abstract

Germanium is a promising anode material for lithium ion batteries because of its high theoretical specific capacity and low operation voltage. However, a significant challenge in using Ge-based anodes is the large volume variation during cycling that causes pulverization and capacity fade. Despite intense studies in the past decade, unsatisfactory cycling stability of the Ge-based electrodes still impedes their widespread applications. In this study, we demonstrate a high-performance electrode through the synergistic combination of a high-capacity Ge film grown on a three-dimensional current collector and an in situ formed poly(vinylidene fluoride)-hexafluoropropene/SiO protective layer. Specifically, the polymer matrix is in continuous contact with the surface of the Ge shell, which provides improved mechanical and ionic transport properties. As a highlight, we present impressive cycling stability over 3000 cycles at 1 C rate with a capacity retention as high as 95.7%. Furthermore, the LiCoO-Ge full battery operates at an average voltage of 3.3 V at 0.5 C and maintains good electrochemical performance, suggesting great potential for applications in energy storage and conversion devices.

Ionic Liquid Based Polymer Gel Electrolytes for Use with Germanium Thin Film Anodes in Lithium Ion Batteries

“…Despite these advantages, utilisation of Ge as an anode material has been hindered by the fact that it undergoes expansion and contraction upon Li alloying and de‐alloying . This leads to cracking and pulverisation of the electrode material which adversely influences the performance and cycle life.…”

A Dual Carbon‐Based Potassium Dual Ion Battery with Robust Comprehensive Performance

“…Nowadays, the demand for smart energy storage devices is on a rapid rise as portable electronic devices and electric vehicles become more and more popular . Among the related devices, lithium (Li) ion batteries (LIBs) dominate the market, owing to their high energy density and matured manufacturing technology . However, the relatively limited reserve and uneven geographical distribution of the lithium resources give a tremendous challenge to LIBs for meeting the continuously increasing requirement on the high performance‐to‐cost ratios.…”

Phosphorization‐Induced Void‐Containing Fe3O4 Nanoparticles Enabling Low Lithiation/Delithiation Potential for High‐Performance Lithium‐Ion Batteries

“…As Figure b displays, the diffusion coefficient of Li + of Fe 3 O 4 is 9.53×10 −12 cm 2 s −1 and 5.30×10 −11 cm 2 s −1 for P−Fe 3 O 4 , which proves the superior Li + kinetics behavior after phosphorization. It is well known that the charge storage mechanism of a cell mainly comes from diffusion‐controlled insertion of Li ion and the surface transfer process induced by pseudo capacitance . We can express the current response at a fixed potential as being the combination of two separate mechanisms, surface capacitive effects and diffusion‐controlled insertion processes [Eq.…”