High‐Voltage LiNi_0.45Cr_0.1Mn_1.45O₄ Cathode with Superlong Cycle Performance for Wide Temperature Lithium‐Ion Batteries

Abstract

Spinel LiNi 0.45 Cr 0.1 Mn 1.45 O 4 synthesized by a scalable solution route combined by high temperature calcination is investigated as cathode for ultralong-life lithium-ion batteries in a wide operating temperature range. Scanning electron microscopy reveals homogeneous microsized polyhedral morphology with highly exposed {100} and {111} surfaces. The most highlighted result is that LiNi 0.45 Cr 0.1 Mn 1.45 O 4 has extremely long cycle performance and high capacity retention at various temperatures (0, 25, 50 °C), indicating that Cr doping is a prospective approach to enable 5 V LiNi 0.5 Mn 1.5 O 4 (LNMO)-based cathode materials with excellent cycling performances for commercial applications. After 1000 cycles, the capacity retention of LiNi 0.45 Cr 0.1 Mn 1.45 O 4 is 100.30% and 82.75% at 0 °C and 25 °C at 1 C rate, respectively. Notably, over 350 cycles at 50 °C, the capacity retention of LiNi 0.45 Cr 0.1 Mn 1.45 O 4 can maintain up to 91.49% at 1 C. All the values are comparable to pristine LNMO, which can be attributed to the elimination of Li y Ni 1−y O impurity phase, highly exposed {100} surfaces, less Mn 3+ ions, and enhancement of ion and electron conductivity by Cr doping. Furthermore, an assembled LiNi 0.45 Cr 0.1 Mn 1.45 O 4 /Li 4 Ti 5 O 12 full cell delivers an initial discharge capacity of 101 mA h g −1 , meanwhile the capacity retention is 82.07% after 100 cycles.

Interfacial Incompatibility and Internal Stresses in All‐Solid‐State Lithium Ion Batteries

“…[40] To improve ionic conductivity at ambient temperatures, more lithium should be incorporated into the structure by adjusting the valence of A and B cations, leading to a series of Li-stuffed fast Li-conducting garnets such as Li 3 Ln 3 Te 2 O 12 (Ln: Y, Pr, Nd, Sm-Lu), [41] Li 3+x Nd 3 -Te 2−x Sb x O 12 (x = 0.05-1.5), [42] Li 5 La 3 M 2 O 12 (M: Nb, Ta, Sb), [43] Li 5.5 La 3 M 1.75 B 0.25 O 12 (M: Nb or Ta; B: In or Zr), [32] Li 6 ALa 2 M 2 O 12 (A: Mg, Ca, Sr, Ba; M: Nb, Ta), [44] Li 7 La 3 M 2 O 12 (M: Zr, Sn), [45] and Li 7.06 M 3 Y 0.06 Zr 1.94 O 12 (M: La, Nb, Ta). The A 3 B 2 C 3 O 12 crystallizes in a face-centered cubic structure with the space group of Ia3d (space group number 230).…”

“…In addition, some of them (B 2 O 3 ) and their derivatives (YPO 4 , Figure 3f) enriched at the GBs will decrease the GB resistance of Li + ion migration. [100] The crystal structure of LLTO, as presented in Figure 4a, has a 3D framework of a corner-sharing TiO 6 octahedron, containing a great amount of defects at A-site. Thin-film NASICON-type fast ionic conductors can be produced through sol-gel, [94] tape casting [95] and aerosol deposition.…”

“…The phases formed will preclude direct mutual elemental diffusion and form an intimate contact with the electrolyte and electrode to decrease the formation of cavities and voids driven by the divergence of crystal structure. S.S. Chi et al [268] deposited a solid polymer electrolyte (PEO + LiTFSI) on two sides of the garnet-type Li 6 (Figure 15b). The Li/LLZO/LiCoO 2 solid cell with cathode-electrolyte interfacial modification exhibited an enhanced cycle stability and rate capability.…”

“…[2] The state-of-the-art electrolytes are usually the lithium salts (LiPF 6 , LiBF 4 , and LiCF 3 SO 3 ) dissolved in organic solvents, i.e., ethylene carbonate, propylene carbonate, polyethylene oxide, and dimethyl carbonate, [3] which exhibit excellent wetting of the electrodes and produce a fast transfer of Li + ions upon charging and discharging. [6] However, successful commercialization of the LNMO is restricted in high-energy LIBs due to electrolyte decomposition and side reaction of the cathodes and liquid electrolytes when operating at high voltages. [4] There is an ever-increasing demand for batteries with a higher energy and power density, although current LIBs offer volumetric and gravimetric energy densities up to 770 Wh L −1 and 260 Wh kg −1 , respectively.…”

High‐Voltage Li‐Ion Full‐Cells with Ultralong Term Cycle Life at Elevated Temperature

“…[16,[20][21][22][23][24] In a word, improving the energy density of cell can be likened as extend the capacity of wood bucket. Additionally, elevated temperature derived from practical cell operation environment would exacerbate the cell deterioration due to the poor thermal stability of typical LiPF 6 carbonate-based electrolyte.…”