Dynamics of Phase Transition in Li–Cu–Sb Anode Material for Rechargeable Lithium Ion Battery

Abstract

This paper deals with the reaction dynamics of phase transition for the electrochemical lithium insertion into Cu 2 Sb intermetallic compound. Electrochemical lithium insertion/removal, alternating current ͑ac͒ impedance technique, and electrochemical calorimetric measurement have been applied in this study. The electrochemical charge-discharge test indicated a large irreversible capacity at the onset of first charging ͑Li insertion͒, where a flat voltage plateau appeared around 0.7 V. In other instances, following cycles showed good reversibility. In addition, the voltage profiles of Ͼ0.7 V region after the second cycle showed higher than the one at the first cycle charging and clear solid solution manner. Thus, the difference of the electrochemical Li insertion mechanism between the first and following cycles caused irreversibility accompanying large electrochemical polarization. To explain the above phenomena, we assumed that the nucleation was rate determined at the onset of phase transition from tetragonal Cu 2 Sb to cubic Li 1+x CuSb. After the phase transition was completed, following cycles did not need to expend the formation of different phase nuclear, showing a good reversibility reaction. The reaction mechanism suggested above was supported by ac impedance and electrochemical calorimetric measurements.

A review of the electrochemical performance of alloy anodes for lithium-ion batteries

“…For example, in a Cu 2 Sb anode Li inserts into the Cu 2 Sb structure to form Li 2 CuSb by concomitant extrusion of Cu and it finally yields Li 3 Sb without disrupting the fcc Sb host sublattice [99]. The intermetallic anodes currently being extensively studied include Cu 6 Sn 5 [44,85,100,101], InSb [64,67,68], Cu 2 Sb [34,66,98,99,102,103] and CoMnSb [103,104]. Several intermetallic anodes have shown stable cycling performance for over 25 cycles [6,85,99,100].…”

Electrochemical investigations of Li2AuSn2

“…This is a field where the study of multinary intermetallic systems presents good possibilities. The investigated examples in this context are ternary systems such as pnictides [22], antimonides [23], and nitrides [24] along with a few other intermetallics [25][26][27].…”

Asymmetry in anodic and cathodic polarization profile for LiFePO4 positive electrode in rechargeable Li ion battery

“…As a result, the cusp of the voltage profile appeared at the very initial part of the current pulse. 10) [ Fig. 4(a)] As mentioned above, mass-transport driven polarization appears generally at a later part of a current pulse.…”

“…In detail, the cusps referred as the feature (i) were related to the nucleation that a FePO 4 (LiFePO 4 ) crystalline-phase domain was formed in the LiFePO 4 (FePO 4 ) domain by charge (discharge). 10) This feature was less significant at lower rate condition and discharge pulse. The feature (ii) indicates a difference in reaction kinetics between charge and discharge at higher rate condition.…”

“…For the two-phase coexistent system, we have reported that nucleation of Li inserted/removed phase plays an important role. 10) In the LiFePO 4 FePO 4 two-phase coexistence system, numerous reports tried to reveal reaction mechanism due to a practical importance mentioned above and fundamental fascination to understand two-phase coexistence reaction.…”