Effect of Carbon Source on Synthesis of Carbon Coated Lithium Titanate

Carbon coated lithium titanate (Li4Ti5O12/C) was obtained by a facile solid state approach in inert Ar atmosphere. The composition, morphology, residual carbon content and Ti valence of the samples were systematically investigated. The carbon content of Li4Ti5O12/C should be optimized, since excess carbon in the composite leads to the reduction of Ti (IV) to form Ti (III), which results in large irreversible capacity of Li4Ti5O12/C. With an optimal carbon content of 0.68wt%, the Li4Ti5O12/C sample shows high rate capabilities and good cycling ability, delivering discharge capacities of 160.8 mAh/g at 5C. The superior high rate properties are ascribed to the specific nanostructures, which enables fast electronic and ionic transport by introducing carbon coating and decreasing the particle size of lithium titanate.

Communication—Lithium Titanate as Mg-Ion Insertion Anode for Mg-Ion Sulfur Batteries Based on Sulfurated Poly(acrylonitrile) Composite

Spinel lithium-titanate Li4Ti5O12 (LTO) is a promising anode material for magnesium batteries due to its non-toxicity, low-cost, zero-strain characteristics and long-term stability. Nevertheless, the application of LTO in a magnesium full cell has been rarely investigated. Herein, we give a proof of concept for the feasibility of LTO as anode in full magnesium ion batteries, which might prevent the passivation of metallic Mg anodes. Mg2+ was electrochemically inserted into LTO prior to cycling against a sulfur-based cathode material, i.e. sulfurated poly(acrylonitrile), SPAN, resulting in stable cycle performance with 800 mAh/gS at 0.3C and high-rate capability.

Electrochemical Cell Preparation on MEMS Chip Surface Inside Scanning Electron Microscope

This paper reports the preparation process of an electrochemical cell consisting of metallic lithium, lithium titanate, and ionic liquid on a MEMS chip surface. Firstly, the MEMS chip is described and the connectivity test of the used pads is performed using voltage contrast imaging. Then the process of electrode preparation using the FIB-SEM technique is described in detail. Special attention is paid to lithium, its degradation during transport into the SEM chamber, and the behavior during ion beam cutting. Finally, a complete battery system was built. It was possible to measure charging/discharging of the model battery system, nevertheless, the functionality was affected by the redeposition of conductive materials on the MEMS surface and charging by an electron beam.

Lithium-Titanate As Electrode Material for Aprotic Systems

This article briefly describes experiments which investigate the mutual compatibility of aprotic solvents with higher fire safety and Lithium Titanate Oxide (LTO) as the negative electrode material for lithium-ion batteries. The work follows the current trend of enhancing fire safety by using new kinds of aprotic solvents along with a new generation of electrode materials which fulfil the intended using of lithium-ion batteries for high power applications, e.g. electric vehicle propulsion. In our work, the examiner of using sulfolane electrolyte (SL) and Li4Ti5O12 (LTO) under various ambient temperatures. The influence of electrolyte on the proper operation and stability of negative electrode material was considered. The measurements were performed in the temperature range from 25 °C up to 80 °C with half-cell connection. Our main objective of these experiments was to prove and investigate a proper operation of an aprotic electrolyte with higher fire safety together with LTO negative material under high ambient temperatures.

New Experimental Approach for the Determination of the Heat Generation in a Li-Ion Battery Cell

With regard to safety, efficiency and lifetime of battery systems, the thermal behavior of battery cells is of great interest. The use of models describing the thermoelectric behavior of battery cells improves the understanding of heat generation mechanisms and enables the development of optimized thermal management systems. In this work, a novel experimental approach is presented to determine both the irreversible heat due to ohmic losses and the reversible heat due to entropy changes directly via heat flow measurements. No additional information about thermal properties of the battery cell, such as heat capacity or thermal conductivity, are required. Thus, the exothermic and endothermic nature of reversible heat generated in a complete charge/discharge cycle can be investigated. Moreover, the results of the proposed method can potentially be used to provide an additional constraint during the identification process of the equivalent circuit model parameters. The described method is applied to a 23Ah lithium titanate cell and the corresponding results are presented.

A New Concept of Air Cooling and Heat Pipe for Electric Vehicles in Fast Discharging

This paper presents the concept of a hybrid thermal management system (TMS) including natural convection, heat pipe, and air cooling assisted heat pipe (ACAH) for electric vehicles. Experimental and numerical tests are described to predict the thermal behavior of a lithium titanate oxide (LTO) battery cell in a fast discharging process (8C rate). Specifications of different cooling techniques are deliberated and compared. The mathematical models are solved by COMSOL Multiphysics® (Stockholm, Sweden), the commercial computational fluid dynamics (CFD) software. The simulation results are validated against experimental data with an acceptable error range. The results specify that the maximum cell temperatures for the cooling systems of natural convection, heat pipe, and ACAH reach 56, 46.3, and 38.3 °C, respectively. We found that the maximum cell temperature experiences a 17.3% and 31% reduction with the heat pipe and ACAH, respectively, compared with natural convection.