Investigating the Perovskite Ag1-3xLaxNbO3 as a High-Rate Negative Electrode for Li-Ion Batteries

Abstract

The broader development of the electric car for tomorrow’s mobility requires the emergence of new fast-charging negative electrode materials to replace graphite in Li-ion batteries. In this area, the design of new compounds using innovative approaches could be the key to discovering new negative electrode materials that allow for faster charging and discharging processes. Here, we present a partially substituted AgNbO3 perovskite material by introducing lanthanum in the A-site. By creating two vacancies for every lanthanum introduced in the structure, the resulting general formula becomes Ag1-3xLax□2xNbO3 (with x ≤ 0.20 and where □ is a A-site vacancy), allowing the insertion of lithium ions. The highly substituted Ag0.40La0.20□0.40NbO3 oxide shows a specific capacity of 40 mAh.g−1 at a low sweep rate (0.1 mV s−1). Interestingly, Ag0.70La0.10□0.20NbO3 retains 64% of its capacity at a very high sweep rate (50 mV s−1) and about 95% after 800 cycles. Ex situ7Li MAS NMR experiments confirmed the insertion of lithium ions in these materials. A kinetic analysis of Ag1-3xLax□2xNbO3 underlines the ability to store charge without solid-state ion-diffusion limitations. Furthermore, in situ XRD indicates no structural modification of the compound when accommodating lithium ions, which can be considered as zero-strain material. This finding explains the interesting capacity retention observed after 800 cycles. This paper thus demonstrates an alternative approach to traditional insertion materials and identifies a different way to explore not-so common electrode materials for fast energy storage application.

Capacitive tendency concept alongside supervised machine-learning toward classifying electrochemical behavior of battery and pseudocapacitor materials

“… The capacitive tendency prediction of experimental voltammograms of ( a ) the well-known pseudocapacitor and battery electrode materials MnO 2 49 , and NMC 50 , compared with the ambiguous CVs of Ag 1-3x La x □ 2x NbO 3 44 , and H 2 TiNbO 18 43 . The predicted ( b ) CVs and ( c ) GCDs of other electrode materials from the literature, as mentioned in Fig.…”

“… Illustration of a experimental CVs and GCDs of different electrode materials including MnO 2 39 , V 2 C 40 , RuO x 41 , LaMnO 3 42 , Ti 3 C 2 T x 15 , H 2 TiNb 6 O 18 43 , Ag 1-3x La x □ 2x NbO 3 44 , Nb 2 O 5 45 , nano-MnS 2 46 , bulk-MoS 2 46 , TiO 2 47 and NaFePO 4 48 , theoretical b CVs and c GCDs undergoing different electrochemical processes. …”

A Novel Approach for Classifying Battery and Pseudocapacitor Materials Using Capacitive Tendency and Supervised Machine Learning

“…Furthermore, the CV signals measured by these experiments are mostly performed in complex situations, and thus to not produce the perfect curves obtained in theoretical demonstrations using various common types of electrode materials (Figures 4). including MnO2, [32] V2C, [33] RuOx, [34] LaMnO3, [35] Ti3C2Tx, [15] H2TiNb6O18, [36] Ag1-3xLax□2xNbO3, [37] Nb2O5, [38] nano-MnS2, [39] bulk-MoS2, [39] TiO2 [40] and NaFePO4 [41] , In this study, these CVs and GCDs were analyzed via supervised ML trained with datasets extracted from over 4,000 scientific papers (see DOI in Supplementary Information). In the following section, various Convolutional Neural Network architectures are validated and selected based on the evaluations explained in the experimental section, by applying the theoretical CV and GCD curves.…”

“…Figure 6 | Capacitive tendency prediction of experimental voltammograms of (a) the wellknown pseudocapacitor and battery electrode materials MnO2, [46] and NMC, [47] respectively, compared with the ambiguous CVs of Ag1-3xLax□2xNbO3, [37] and H2TiNbO18 [36], respectively.…”

Hexagonal Tungsten Bronze H0.25Cs0.25Nb2.5W2.5O14 as a Negative Electrode Material for Li-Ion Batteries

“…Reducing the particle size increases the electronic and ionic conductivities but decreases the density of the batteries due to the lower practical density. − The creation of cationic vacancies and fluorine or chlorine doping are also promising ways to increase power density. − On the other hand, finding new materials with intrinsic good ionic and electronic conductivities seems interesting. In this sense, Goodenough’s group proposed TiNb 2 O 7 in 2011. − This is a so-called Wadsley–Roth material because it has blocks of octahedra (MO 6 ) organized similarly as ReO 3 , and these blocks share their edges forming a 3D structure.…”