Conductive Li_3.08Cr_0.02Si_0.09V_0.9O₄ Anode Material: Novel “Zero‐Strain” Characteristic and Superior Electrochemical Li⁺ Storage

Abstract

some issues, such as insufficient battery longevity, safety risks, and limited driving ranges/speeds. [1] Thus, high-performance LIBs with long-term cycle life, good safety, and high energy/power densities are pursued. Particularly, the cycle life is essential in actual applications. Capacity decay of LIBs primarily derives from the fact that electrode materials generally suffer mechanical stresses since the strains associated with phase transitions or lattice-parameter variations during Li + insertion-extraction are generally obvious. Mismatched lattice parameters between dominated and coexisting phases in two-phase reactions or large unitcell volume variations in solid-solution reactions can lead to the fracture phase interfaces, thus significantly contributing to the capacity decay. These issues can be completely avoided in "zero-strain" electrode materials whose unit-cell volume variations are negligible (<1%) during discharging-charging. Spinel Li 4 Ti 5 O 12 , a typical "zero-strain" anode material, has been demonstrated for thousands cycles in LIBs. This excellent cycling stability stems from its tiny volume variation (≈0.2%) upon cycling. [2] Other "zero-strain" anode materials, such as LiCrTiO 4 and LiY(MoO 4 ) 2 , also present decent cycling stability. [3] Clearly, "zero-strain" materials are ideal for a long operational energy storage. To the best of our knowledge, however, the very limited "zero-strain" anode materials explored for LIBs so far commonly present small reversible capacities "Zero-strain" compounds are ideal energy-storage materials for long-term cycling because they present negligible volume change and significantly reduce the mechanically induced deterioration during charging-discharging. However, the explored "zero-strain" compounds are very limited, and their energy densities are low. Here, γ phase Li 3.08 Cr 0.02 Si 0.09 V 0.9 O 4 (γ-LCSVO) is explored as an anode compound for lithium-ion batteries, and surprisingly its "zero-strain" Li + storage during Li + insertion-extraction is found through using various state-of-the-art characterization techniques. Li + sequentially inserts into the 4c(1) and 8d sites of γ-LCSVO, but its maximum unitcell volume variation is only ≈0.18%, the smallest among the explored "zero-strain" compounds. Its mean strain originating from Li + insertion is only 0.07%. Consequently, both γ-LCSVO nanowires (γ-LCSVO-NW) and micrometer-sized particles (γ-LCSVO-MP) exhibit excellent cycling stability with 90.1% and 95.5% capacity retention after as long as 2000 cycles at 10C, respectively. Moreover, γ-LCSVO-NW and γ-LCSVO-MP respectively deliver large reversible capacities of 445.7 and 305.8 mAh g −1 at 0.1C, and retain 251.2 and 78.4 mAh g −1 at 10C. Additionally, γ-LCSVO shows a suitably safe operating potential of ≈1.0 V, significantly lower than that of the famous "zero-strain" Li 4 Ti 5 O 12 (≈1.6 V). These merits demonstrate that γ-LCSVO can be a practical anode compound for stable, high-energy, fast-charging, and safe Li + storage.The ORCID identificati...

Zero‐Strain High‐Capacity Silicon/Carbon Anode Enabled by a MOF‐Derived Space‐Confined Single‐Atom Catalytic Strategy for Lithium‐Ion Batteries

“…[1][2][3] However, subject to intrinsic lithium storage mechanism, LIBs suffer from large volume change of electrode materials during lithiation and delithiation processes, which unavoidably cause pulverization of electrode and overall performance deterioration of batteries. Under such background, a category of electrode materials so called "zero-strain" or "low-strain" materials undergone small volume change during cycling has been developed, such as anode materials of CaV 4 O 9 , [4] Li 4 Ti 5 O 12 , [5,6] TiNb 2 O 7 , [7] LiCrTiO 4 , [8] LiY(MoO 4 ) 2 , [9] and Li 3.08 Cr 0.02 Si 0.09 V 0.9 O 4 , [10] and cathode materials of LiCoO 2 [11] and Li 1.2 Ni 0.4 Ru 0.4 O 2 . [12] To date, zero-strain electrode materials reported are merely limited to single crystals.…”

Atomic Short‐Range Order in a Cation‐Deficient Perovskite Anode for Fast‐Charging and Long‐Life Lithium‐Ion Batteries

“…The in situ solid-state battery was fabricated with a well-designed and optimized focused ion beam (FIB) to enable the electrochemical activity of the battery. [20,26,41] Figure 4a displays the SEM image of an in situ solid-state battery composed of a CNO anode, Li 6.4 La 3 Zr 1.4 Ta 6 O 12 (LLZO) solid-state electrolyte, and a LiFePO 4 cathode. The morphology features of the CNO anode can be determined from the low-magnification TEM image, where the image contrast is crystalline diffraction contrast, suggesting the great electrochemical activity of CNO after FIB.…”

In situ interfacial architecture of lithium vanadate-based cathode for printable lithium batteries

“…Metal vanadates have caused wide interest because of their low cost, high specific capacity, and electric-neutrality structures for lithiation/delithiation ( Ni et al., 2019 ; Liu et al., 2019 ). Compared to commercial graphite and lithium titanate, lithium-rich vanadates have attracted much attention due to low volume swelling and stable cycling, safe working potential, and high energy density ( Mo et al., 2017 ; Liao et al., 2017 ; Liang et al., 2020 ). Very recently, disordered rock salt Li 3 V 2 O 5 was synthesized by V 2 O 5 lithiation, which exhibits reversibly cycle two Li ions with a specific capacity of 266 mA h g −1 ( Liu et al., 2020a ).…”