Li_2.0Ni_0.67N, a Promising Negative Electrode Material for Li-Ion Batteries with a Soft Structural Response

Abstract

/Ni + redox couple is involved and the electron transfer is combined with the reversible accommodation of Li + ions in the cationic vacancies. The structural response is fully reversible and minimal, with a maximal volume variation of 2%. As a consequence, a high capacity of 200 mAh g -1 at C/10 is obtained with an excellent capacity retention, close to 100% even after 100 cycles, which makes Li2.0(1)Ni0.67(2)N a promising negative electrode material for Li-ion batteries.

Kinetic insights into LixNi0.67N (1.67 ≤ x ≤ 2.17), a quasi “zero-strain” negative electrode material for Li-ion battery

“…Indeed, the new semicircle is decreasing with decreasing x values and completely disappears for x = 1.67. This reversible behavior evidenced from EIS experiments is in good agreement with the high structural [21] and electrochemical reversibility shown previously (Figure 3a). In addition, the lack of significant impedance variation between the fully oxidized and fully reduced states (|Z| x=1.67 = 322 Ω, i.e., 161 Ω cm 2 |Z| x=2.17 = 212 Ω, i.e., 106 Ω cm 2 ) confirms the promising properties of LNN as stable Li intercalation host lattice.…”

“…Nitridonickelate-based compounds, with general formula Li 3-xy Ni x N (1 ≤ y ≤ 2, referred as Ni oxidation state; 0.20 ≤ x ≤ 0.67, referred as Ni content), exhibits a capacity of 120-200 mAh g -1 in the 1.25 V-0.02 V potential range combined with good cycling performance. In the Li-Ni-N system, Li 2.0 Ni 0.67 N (LNN) with the highest Ni content was identified as the most promising composition, providing the highest specific capacity of 200 mAhg −1 available at an average working potential of 0.5 V [21]. Moreover, as demonstrated in this work, LNN exhibits almost 100% capacity retention upon cycling at C/10 and more than 88% at 1C over at least 100 cycles.…”

“…Moreover, as demonstrated in this work, LNN exhibits almost 100% capacity retention upon cycling at C/10 and more than 88% at 1C over at least 100 cycles. Such remarkable cycling properties were ascribed to the "zero-strain" structural behavior of LNN upon cycling [21], the structural response of LNN during reduction and oxidation consisting in a solid solution behavior involving the Ni 2+ /Ni + redox couple, with reversible accommodation of Li + ions in the numerous cationic vacancies of its stable hexagonal structure. Such original structural behavior of LNN associated to the promising electrochemical properties of this anode material deserves a detailed kinetics investigation, which to our knowledge, has not yet been conducted for the nitridonickelate system.…”

Reversible Electrochemical Lithium-Ion Insertion into the Rhenium Cluster Chalcogenide–Halide Re6Se8Cl2

“…From the onset of the 1.7 V plateau to 2 ee of reduction, there is a structural change as the original (001) reflection loses intensity and a new peak at d = 8.46 Å appears, coincident with a 4% lattice expansion indicative of Li + insertion within the interlayer space. Considering that there is an emergence of a new peak rather than a peak shift, this initial insertion of Li + causes a new structural configuration within the material. , After 4 ee, there is a voltage drop corresponding to a contraction in the (001) plane from 8.46 to 8.38 Å. At this point, the intercalation of Li + ions has a significant impact on the structural configuration.…”

“…Considering that there is an emergence of a new peak rather than a peak shift, this initial insertion of Li + causes a new structural configuration within the material. 31,32 After 4 ee, there is a voltage drop corresponding to a contraction in the (001) plane from 8.46 to 8.38 Å. At this point, the intercalation of Li + ions has a significant impact on the structural configuration.…”