A lithium salt additive Li2ZrF6 for enhancing the electrochemical performance of high-voltage LiNi0.5Mn1.5O4 cathode

High-Throughput Computational Screening of Li-Containing Fluorides for Battery Cathode Coatings

“…The 19 candidate coatings also offer substantially higher oxidation limits (≥5 V) than the cathode materials, making it possible to pair them with extremely high-voltage cathodes such as layered lithium-rich oxides (∼4.5 V), nickel-rich oxides (∼4.3 V), and spinel LiNi 0.5 Mn 1.5 O 4 (∼4.7 V) . For example, Li 2 ZrF 6 exhibits an oxidation limit of 6.56 V as a coating for a LiNi 0.5 Mn 1.5 O 4 cathode, which explains its previously reported good performance . Because the cations in the coatings are already fully oxidized, the oxidation limits are controlled by oxidation of the anions.…”

“…Recently, Xie et al and Zhao et al reported LiAlF 4 -coated cathode materials (LiNi 0.8 Mn 0.1 Co 0.1 O 2 and Li 1.2 Ni 0.2 Mn 0.6 O 2 ) that possessed improved rate capability and cycling stability with the LiAlF 4 coating exhibiting good ionic conductivity as well as electrochemical and chemical stability. Fan et al reported that coating Li 2 ZrF 6 on a LiNi 0.5 Mn 1.5 O 4 cathode material improved the cycling ability and rate property of the cells. In addition, a Li 2 TiF 6 -coated Li 1.17 Ni 0.17 Co 0.1 Mn 0.56 O 2 cathode material was also reported to exhibit high rate capability, long cycling ability, and improved thermal stability .…”

“…As the candidate coatings on the cathode surface are in contact with LiPF 6 -based liquid electrolytes, the chemical stability between the coating and liquid electrolyte is described by the coating/HF reactions. The screening returned 10 promising coating candidates including two experimentally studied compounds, Li 2 ZrF 6 and Li 2 TiF 6 , which have been demonstrated to satisfy the necessary combination of excellent phase stability, electrochemical stability, chemical stability, and ionic conductivity. We further discuss the relative merits of these candidate coatings compared with commonly used oxide and fluoride coatings.…”

7‐Hydroxycoumarin as a Novel Film‐Forming Additive for LiNi0.5Mn1.5O4 Cathode at Elevated Temperature

“…[39][40][41] Many additives such as LiBOB, thiophene, MPL, PTS, SDM, AMSL, TPFPS, DPE and Li 2 ZrF 6 have been used to improve the electrochemical performance of LiNi 0.5 Mn 1.5 O 4 at elevated temperature, but the achievement is still not satisfying yet. [42][43][44][45][46][47][48][49][50][51] 7-HC (Scheme 1) has a phenolic hydroxyl functional group, so it is easy to be oxidized preferentially, thereby avoiding oxidation of other substances. [52,53] In addition, 7-HC has not been used as an additive to improve the electrochemical performance of cell.…”

Role of Al-doping with different sites upon the structure and electrochemical performance of spherical LiNi0.5Mn1.5O4 cathode materials for lithium-ion batteries

“…The applied electrolyte, including salts, solvents and additives, has been optimized to enhance tolerance and stability in harsh electrochemical environments. [8][9][10][11][12][13][14][15] More attention has been paid to solving the undesirable features of LNMO materials. Several methods have been adopted to regulate the microstructure and aggregation morphology of precursor and LNMO materials: ball milling, 16 solid-state reaction, 17 sol-gels, 18 solvothermal synthesis, 19 template synthesis 20 and co-precipitation.…”