Spontaneous repairing liquid metal/Si nanocomposite as a smart conductive-additive-free anode for lithium-ion battery

Abstract

Silicon is a promising candidate for negative electrodes due to its high theoretical specific capacity (~3579 mAh g -1 ) and low lithiation potential (~0.40 V vs Li). However, its practical applications in battery have been inhibited by the large volume change (~400%) induced by Li + -insertion into Si lattices. Here, we attempt to resolve this issue at a fundamental level, and report for the first time a novel liquid metal (LM)-mediated spontaneous repairing conductive-additive-free Si anode for Li-ion battery. The fluidity of LM ensures the eternal contact between Si and the conducting-network during its repeated electrochemical reactions.The as-prepared nano-composite of LM/Si leads to superior performances as characterized by high capacity utilization (2300 mAh g -1 at 500 mA g -1 ), long-term stability (968 mAh g -1 after 1500 charge-discharge cycles at 8 A g -1 with 81.3% retention), high rate capability (360 mAh g -1 at 20 A g -1 , equivalence of 55 C, or full charge/discharge in 65 seconds), and, in particular, an extra-ordinarily high initial coulombic efficiency (95.92%), which is not only the highest reported for Si to the best of our knowledge, but also higher than the mature graphitic carbon anodes. The unique approach described in this work not only resolves the basic stress challenges faced by the promising but often problematic alloy-type materials; in broader context it also provides a universal inspiration to all electrode materials whose electric properties suffer from extreme mechanic upheavals induced by the electrochemical strains during the cell reactions.

Improved performances of lithium-ion batteries using intercalated a-Si–Ag thin film layers as electrodes

“…A similar phenomenon of the poor rate dependence can be found in previous research as well. 11,[55][56][57] Fig . 5 shows the surface morphologies of the samples before and aer 150 cycles.…”

Self‐Healing Materials for Energy‐Storage Devices

“…Liu and co‐workers [ 186 ] illustrated that the GeP anode presented a remarkable self‐healing capability by reconstruction of its original layered crystal structure during charging, thus offering outstanding cycling performances. Liquid alloys such as Na‐K alloy, [ 187 ] Ga‐Sn alloy, [ 188,198 ] Ga‐In alloy, [ 199 ] and Ga‐In‐Sn alloy, [ 200 ] benefiting from their inherent self‐healing properties and high theoretical capacities, were developed as anodes for LIBs or SIBs. Besides, self‐healing magnetic Nd 2 Fe 14 B microparticles [ 189 ] and the shape memory NiTi alloys [ 190 ] were also reported in ESDs.…”

Applications of Low‐Melting‐Point Metals in Rechargeable Metal Batteries

“…Maldonado and colleagues prepared in situ Ge microwire films with minor liquid Ga‐In‐Cu metal as the core deposited on a Cu substrate, retaining a high capacity of 1215 mAh g −1 after 40 cycles at the 0.1 C rate [56] . Deng's group synthesized a quaternary alloy LM/Si (LM=Ga‐In‐Sn liquid metal) anode by a simple stirring process [53] . This composite anode exhibits a long cycling life of 1500 cycles at 8 A g −1 and excellent rate capability of 360 mAh g −1 at the high current density of 20 A g −1 .…”