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Abstract A carbon coated commercial lithium titanium oxide (Li 4 Ti 5 O 12 ; LTO) was acoustically mixed with nano-sized AlF 3 and heat treated to form a simultaneous coating layer of carbon and AlF 3 on LTO particles. The surface modified LTO samples were characterized by a variety of means such as X-ray diffraction, Fourier transform infrared spectrometer, high-resolution transmission electron microscope, and inductively coupled plasma mass spectrometry. The results indicate that both carbon and AlF 3 layers exist on the surface of LTO particles and that the distribution of the carbon and AlF 3 differs depending on post heat treatment temperature. The carbon and AlF 3 coating layers formed by optimal post heat treatment at 350 °C significantly improves electrochemical performance, which increases charge capacity by 30% over the pristine LTO after 50 cycles at a high current density of 5C. Thus, LTO with a simultaneous coating layer of carbon and AlF 3 formed by acoustic mixing and post heat treatment shows a potential to further improve commercially-optimized carbon-coated LTO by alleviating its inherently low conductivity. This is an effective way to stabilize the interface between LTO particles and electrolyte, and is a practical approach to promote the wide usage of LTO, one of the most potent anode materials. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

In our recent work, we demonstrated that the use of bio-derived rosin as a binder additive could improve the electrochemical performance of lithium titanium oxide (LTO) anodes. As a sequential study, four representative modified rosin-derivatives are used as additives for polyvinylidene difluoride (PVdF) binders in order to further improve the cell performance of LTO electrodes. The rosin derivative modified via simple hydrogenation retains carboxylic acids and is favorable to lithium ion transport when compared to the modified rosins, which loose these functional groups via esterification. The hydrogenated rosin additive increases cyclic capacities, initially by 10 mAh g − 1 and more so at high current charge/discharge rates. [ABSTRACT FROM AUTHOR]

The lifetime performance of lithium-ion batteries is a critical issue for automobile and stationary applications. The difference in the side-reaction current (I SR) of electrodes causes deviations of the state of charge (SOC) of the electrodes leading to the capacity fading of lithium-ion batteries. Establishment of a method to measure the I SR is important for understanding the capacity fading mechanism. We report herein that a novel and simple method to determine the I SR in lithium-ion batteries, the self-discharge test, was developed and applied to lithium-ion cells with lithium titanium oxide (Li[Li 1/3 Ti 5/3 O 4 , LTO), lithium aluminum manganese oxide (Li[Li 0.1 Al 0.1 Mn 1.8 O 4 , LAMO), and lithium nickel manganese oxide (Li[Ni 1/2 Mn 3/2 O 4 , LiNiMO) as electrodes. According to the self-discharge test results, the I SR of LTO is affected by another electrode of LAMO or LiNiMO. The I SR of LTO in LTO/LiNiMO cells larger than that in LTO/LAMO cells is explained by the additional- I SR of LTO, which results from side reactions such as the reduction of oxidized products generated at the positive electrode. The side reactions at the positive electrode are accelerated with increasing electrode potential, meaning that the higher potential of the positive electrode resulted in the larger additional- I SR of LTO. The real side-reaction current of the LTO electrode in lithium-ion cells is the sum of the intrinsic and the additional current (real- I SR = intrinsic- I SR + additional- I SR). • A novel and simple method to determine the side-reaction current (I SR) in lithium-ion batteries was developed. • The LTO side-reaction current I SR was affected by the other LAMO and LiNiMO electrodes. • The real side-reaction current (real- I SR) in LIB is the sum of the intrinsic and the additional current. • The real- I SR of the LTO-negative electrodes was significantly larger than the intrinsic- I SR due to the additional- I SR. [ABSTRACT FROM AUTHOR]