A Truncated Manganese Spinel Cathode for Excellent Power and Lifetime in Lithium-Ion Batteries

Abstract

Spinel-structured lithium manganese oxide (LiMn(2)O(4)) cathodes have been successfully commercialized for various lithium battery applications and are among the strongest candidates for emerging large-scale applications. Despite its various advantages including high power capability, however, LiMn(2)O(4) chronically suffers from limited cycle life, originating from well-known Mn dissolution. An ironical feature with the Mn dissolution is that the surface orientations supporting Li diffusion and thus the power performance are especially vulnerable to the Mn dissolution, making both high power and long lifetime very difficult to achieve simultaneously. In this investigation, we address this contradictory issue of LiMn(2)O(4) by developing a truncated octahedral structure in which most surfaces are aligned to the crystalline orientations with minimal Mn dissolution, while a small portion of the structure is truncated along the orientations to support Li diffusion and thus facilitate high discharge rate capabilities. When compared to control structures with much smaller dimensions, the truncated octahedral structure as large as 500 nm exhibits better performance in both discharge rate performance and cycle life, thus resolving the previously conflicting aspects of LiMn(2)O(4).

Review—Multifunctional Materials for Enhanced Li-Ion Batteries Durability: A Brief Review of Practical Options

“…The corresponding improvements in capacity retention at end-of-test (EOT), over cells with the baseline separator, are 75%, 90% and 125%, respectively for poly-BPA, poly-PEI and Na 4 EDTA. 64 The faradaic efficiency (FE) of all cells with chelating separators is also higher than FE of baseline cells. Furthermore, the FE for the baseline cells steadily decreases during the second half of the cycling test at 55…”

“…Some of the proposed mitigation measures demonstrate great ingenuity and technical virtuosity, but may have limited effectiveness and be of little practical utility due to cost considerations. For example, while controlling the crystal facets at the surface of active materials during synthesis 64 appears as an elegant and intellectually appealing mitigation measure for Mn dissolution, this only reduces and does not eliminate the Mn dissolution, at a cost which is unlikely to match that of the polycrystalline materials used in mass-produced batteries, which the have various crystals planes at the active material particle surfaces.…”

Surface phase diagram and stability of (001) and (111)LiMn2O4spinel oxides

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] However, there are several drawbacks of LMO including a severe capacity fade during cycling due to a Jahn-Teller (JT) distortion in the oxide material, as well as dissolution of Mn in the electrolyte. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Since the dissolution can initiate from the surfaces of LMO particles, a complete understanding of the surface structure and stability is the key to suppress the Mn loss and to overcome the current limitations of the spinel LMO as a Li-ion battery cathode. [2][3][4]11,12 The electrochemical performance of batteries with LMO cathodes depends on multiple factors (e.g.…”

“…), and in particular, the morphology of the LMO particles obtained with different synthesis conditions can lead to diverse electrochemical properties. [5][6][7] For example, Kim et al demonstrated that the octahedron-shaped LMO cathode particles dominated by (111) surfaces exhibit a superior capacity retention compared to the platelet-shaped LMO dominated by (001) surface. 7 These findings suggest that the (111) LMO surface is more resistant to Mn dissolution, while other surfaces such as (001) are more likely to be more prone to it.…”

Tuning three-dimensional TiO2 nanotube electrode to achieve high utilization of Ti substrate for lithium storage

“…Compared to graphite, TiO 2 has a higher lithium intercalation potential (1.75 V vs. Li + /Li), enabling it to avoid the deposition of metallic lithium, and it has higher capacity for Li + intercalation/de-intercalation [4,5]. [6][7][8][9].…”