The Role of Sei in Lithium and Lithium Ion Batteries

Abstract

This paper presents and discusses fundamental processes taking place at the lithium and LixC6 electrode/electrolyte interphases and models for these interphases. We deal with both nonaqueous and polymer (dry and gel) electrolytes, graphitized and nongraphitized carbonaceous materials as anodes for Li-ion batteries. Each electrode/electrolyte combination has its own unique features and problems but there are some general phenomena common to all of them. Issues to be reviewed include SEI composition, morphology and formation reactions, graphite surface modifications including chemical bonded SEI and micro channels formation, electrode degradation processes, lithium deposition-dissolution and intercalation-deintercalation mechanisms, rate-determining steps (RDS), electrolyte and electrode parameters and conditions affecting the above mentioned processes. Technologyrelated issues are emphasized.

Performance study of commercial LiCoO2 and spinel-based Li-ion cells

“…This capacity fade is caused by various mechanisms, which depend on the electrode materials and also on the protocol adopted to charge the cell. Capacity fade in Li-ion cells can be attributed to unwanted side reactions that occur during overcharge or discharge, which causes electrolyte decomposition, passive film formation, active material dissolution and other phenomena [1][2][3][4][5][6][7][8][9][10].…”

Lithium intercalation behavior of surface modified carbonaceous materials

“…The SEI directly affects the carbon anode (and the cell) performance parameters such as the lithium intercalation/deintercalation capacity, cycling efficiency, charge/discharge rate, cycle life, shelf life and safety. While this phenomena at the lithium/organic electrolyte interphase have been studied extensively (7)(8)(9)(10)(11)(12)(13), the actual morphology of the SEI is regarded as complex. It is believed to change with the stage of charge and in different electrolytes (8,14).…”

“…While this phenomena at the lithium/organic electrolyte interphase have been studied extensively (7)(8)(9)(10)(11)(12)(13), the actual morphology of the SEI is regarded as complex. It is believed to change with the stage of charge and in different electrolytes (8,14). Peled and co-workers (8)(9)(10)15) have discussed the SEI processes in great details.…”

“…It is believed to change with the stage of charge and in different electrolytes (8,14). Peled and co-workers (8)(9)(10)15) have discussed the SEI processes in great details. Aside from the surface area (16), factors which influence the formation of the solid-electrolyte interface (SEI) are much less understood.…”

“…Aside from the surface area (16), factors which influence the formation of the solid-electrolyte interface (SEI) are much less understood. In widely-used EC, DEC, DMC and PC-based electrolytes, an SEI layer containing primarily Li 2 CO 3 is postulated (8, 15). A number of practical means to reduce the irreversible capacity have been considered.…”