Realizing High Voltage Lithium Cobalt Oxide in Lithium-Ion Batteries

Abstract

The combination of high voltage cathode and metal or graphite anodes provides a feasible way for future high-energy batteries. Among various battery cathodes, lithium cobalt oxide is outstanding for its excellent cycling performance, high specific capacity, and high working voltage and has achieved great success in the field of consumer electronics in the past decades. Recently, demands for smarter, lighter, and longer standby-time electronic devices have pushed lithium cobalt oxide-based batteries to their limits. To obtain high voltage batteries, various methods have been adopted to lift the cutoff voltage of the batteries above 4.45 V (vs Li/Li+). This review summarizes the mechanism of capacity decay of lithium cobalt oxide during cycling. Various modifications to achieve high voltage lithium cobalt oxide, including coating and doping, are also presented. We also extend the discussion of popular modification methods for electrolytes including electrolyte additives, quasi-solid electrolytes, and electrode/electrolyte interfaces.

Stabilizing electrode–electrolyte interfaces to realize high-voltage Li||LiCoO2 batteries by a sulfonamide-based electrolyte

“…For the cathode, an effective approach to increase the energy output is to extend the operating voltages, especially for LiCoO 2 (LCO), the dominant cathode in current LIBs for consumer electronics 5,6 because of its superior volumetric energy density (E v ). However, the charging voltage in commercial products 7 is usually limited below 4.35 V Li , yielding a discharge capacity of B165 mA h g À1 (Li 1Àx CoO 2 , x = B0.6), still far away from the theoretical maximum (274 mA h g À1 ), because the substantial increase in capacity achieved at higher charging cut-off voltage (Z4.5 V Li ) would come at the expense of rapid decay of capacity and efficiency.…”

Revealing the correlation between structure evolution and electrochemical performance of high-voltage lithium cobalt oxide

“…Since lithium cobalt oxide (LCO) was firstly commercialized in the 1990s, it has been dominating the consumer electronics markets for many decades because of its high tap density, high volumetric energy density, and superior power capability. Generally, increasing the upper cut-off voltage of LCO readily delivers more capacity, but this is also accompanied by bulk and interfacial instability issues featured by irreversible structural phase transformations and electrolyte side reactions, leading to a deterioration in the electrochemical performance [1][2][3]. Fortunately, the cut-off voltage of LCO has been increased to 4.45 V (vs. graphite anode) with the corresponding volumetric energy density of 700 Wh/L under the help of surface and bulk engineering [4,5].…”

A Study of Model‐Based Protective Fast‐Charging and Associated Degradation in Commercial Smartphone Cells: Insights on Cathode Degradation as a Result of Lithium Depositions on the Anode

“…Mitigating the issues with LCO at high potentials has attracted a lot of research interest and helped to improve the stability of LCO using surface modifications, including coatings, [ 14–18 ] and doping with a variety of elemental compositions. [ 18–20 ] Today, these efforts have led to LCO having the largest market share in terms of battery use for mobile consumer applications. [ 2,4 ] Besides offering high cycling stability for mobile consumer applications, another requirement for LIBs utilized in smartphones and other portable electronic devices is the capability of fast‐charging, without compromising cycle life.…”