First‐Principles Calculations of Lithium‐Ion Migration at a Coherent Grain Boundary in a Cathode Material, LiCoO₂

Abstract

Results of theoretical calculations are reported, examining the effect of a coherent twin boundary on the electrical properties of LiCoO(2) . This study suggests that internal interfaces in LiCoO(2) strongly affect the battery voltage, battery capacity, and power density of this material, which is of particular concern if it is used in all-solid-state Li-ion batteries.

The graph-theoretic minimum energy path problem for ionic conduction

“…15,25 Because the equation is an exponential function of E m with a 2 ν as a pre-exponential factor, E m is generally more important than a and ν.…”

“…First-principles calculation is a powerful tool for analyzing defect formation and conduction mechanisms. [1][2][3][4][5][6][7][8][9][10][11] Although first-principles calculations with the nudged elastic band method (NEBM) can reveal a trajectory and an activation energy between two particular states, [12][13][14][15] the whole conduction path must be assumed before the calculations. First-principles molecular dynamics (FPMD) simulates atomic behaviors in complex crystals at finite temperatures.…”

Atomic‐Scale Monitoring of Electrode Materials in Lithium‐Ion Batteries using In Situ Transmission Electron Microscopy

“…First-principles calculations have shown that there is three orders of magnitude increase of the diffusion constant for Li migration along TBs than that across TBs in LiCoO 2 . [91] An in situ STEM study of a single SnO 2 nanowire with TBs confirmed that Li ions preferentially intercalated near the (101) TB, which acted as a conduit for Li-ion diffusion in the nanowire. As shown in Figure 7, the lithiated SnO 2 nanowire exhibits darker-contrast stripes along the TB and in the [001] direction than the pristine nanowire exhibits; these stripes indicate Li-ion intercalation.…”

A design strategy of large grain lithium-rich layered oxides for lithium-ion batteries cathode

“…The cathode material is a key component to determine the capacity, cyclability and power/energy density of LIBs. However, conventional cathode materials, such as LiCoO 2 , LiMn 2 O 4 , LiFePO 4 and LiNi 1/3 Co 1/3 Mn 1/3 O 2 , all deliver low discharge capacity far below 200 mAh g À1 , indicating that alternative positive electrode materials with higher energy density than conventional cathode materials are required to meet the design needs of future rechargeable batteries [3][4][5][6][7].…”