Enhancement of Y5−xPrxSb3−yMy (M = Sn, Pb) Electrodes for Lithium- and Sodium-Ion Batteries by Structure Disordering and CNTs Additives

Volodymyr Pavlyuk,Wojciech Ciesielski,Nazar Pavlyuk,Karolina Kluziak,Agnieszka Balińska ,Damian Kulawik

doi:10.3390/ma14154331

Abstract

The maximally disordered (MD) phases with the general formula Y5−xPrxSb3−yMy (M = Sn, Pb) are formed with partial substitution of Y by Pr and Sb by Sn or Pb in the binary Y5Sb3 compound. During the electrochemical lithiation and sodiation, the formation of Y5-xPrxSb3-yMyLiz and Y5−xPrxSb3−yMyNaz maximally disordered–high entropy intermetallic phases (MD-HEIP), as the result of insertion of Li/Na into octahedral voids, were observed. Carbon nanotubes (CNT) are an effective additive to improve the cycle stability of the Y5−xPrxSb3−yMy (M = Sn, Pb) anodes for lithium-ion (LIBs) and sodium-ion batteries (SIBs). Modification of Y5−xPrxSb3−ySny alloys by carbon nanotubes allowed us to significantly increase the discharge capacity of both types of batteries, which reaches 280 mAh · g−1 (for LIBs) and 160 mAh · g−1 (for SIBs), respectively. For Y5−xPrxSb3−yPby alloys in which antimony is replaced by lead, these capacities are slightly smaller and are 270 mAh · g−1 (for LIBs) and 155 mAh · g−1 (for SIBs), respectively. Results show that structure disordering and CNT additives could increase the electrode capacities up to 30% for LIBs and up to 25% for SIBs.

Highlights

Intermetallics with sufficiently large interatomic voids are favorable for the insertion of lithium or sodium ions
The intermetallic compound LaSn3 (AuCu3 -type) as a possible negative electrode for the lithium-ion batteries was described by Vaughey et al [1]
Disordered and high-entropy alloys are suitable for the development of advanced materials with unique properties that cannot be achieved by conventional materials based only on ordered phases

Summary

Introduction

Intermetallics with sufficiently large interatomic voids are favorable for the insertion of lithium or sodium ions. The intermetallic compound LaSn3 (AuCu3 -type) as a possible negative electrode for the lithium-ion batteries was described by Vaughey et al [1]. The insertion of lithium atoms into octahedral voids of hexagonal Zr5 Sn3 and RE5 M3 (RE = Y, La and Gd; M = Ge and Sn) binary phases were described earlier by us [2,3,4]. The M components (Ge or Sn or Pb atoms) are located at the additional 6g site. For this binary structure, the presence of an octahedral void in the 2b site is typical. We detected the new ternary phase of Tb5 LiSn3 with fully filled 2b site (Hf5 CuSn3 structure type) during the systematic study of the alloys of

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Results

Conclusion