Comparative study of carbon free and carbon containing Li4Ti5O12 electrodes

Abstract

Traditionally electrodes for lithium ion batteries are manufactured using carbon additives to increase the conductivity. However, in case of lithium titanate, Li4Ti5O12 (LTO), carbon free electrodes have gathered some interest lately. Therefore two LTO materials synthetized using the same synthesis but different end milling process resulting in materials with different particle size and surface area are compared here using electrodes manufactured with and without carbon additives. Both LTO samples (LTO-SP with small primary particle size and high surface area, and LTO-LP with larger primary particle size and small surface area) produce similar capacities and voltages with or without carbon additives at low C-rates at the room temperature. However, at high C-rates and/or sub-zero temperatures electrodes with carbon additives produce higher capacities and smaller ohmic losses and this behavior is more pronounced for the LTO electrodes with smaller primary particle size and larger surface area. These results show that the feasibility of carbon free LTO electrodes depends on the properties of LTO affecting the morphology of the electrode and consequently, the transport properties. This is most pronounced under conditions where electron and Li + ion transfer become limiting (high C-rates and low temperature).

Recent advances of Li4Ti5O12 as a promising next generation anode material for high power lithium-ion batteries

“…Hence, carbon coating has been demonstrated to be useful in enhancing the electrical conductivity of Li 4 Ti 5 O 12 , [142][143][144][145][146] and it can also restrict gas evolution by preventing the electrode from contacting with the electrolyte directly. 147 Moreover, the carbon layer prevents the Li + from diffusing into the bulk Li 4 Ti 5 O 12 in some extent. 1 Ordinarily, carbon coating is obtained by adding the carbon precursor (glucose, 148 sucrose 149 and pitch 150 ) to Li 4 Ti 5 O 12 (or its precursor), mixing evenly, and then sintering at a high temperature in an inert or reducing atmosphere.…”

Understanding the Stabilizing Effects of Nanoscale Metal Oxide and Li–Metal Oxide Coatings on Lithium-Ion Battery Positive Electrode Materials

“…In addition, increasing the Li content in lithium titanate can increase its ionic conductivity and improve its electrochemical performance. 22,25 In this work, the effect of the surface modification of NMC622 electrodes via TiO x and Li x Ti y O z has been studied. ALD was used to modify the surface of the positive electrode material as this method can enhance the interfacial zone between the electrode and the electrolyte by providing a highly uniform and stable coating.…”

Facile Synthesis of Carbon‐Coated Li3VO4 Anode Material and its Application in Full Cells

“…Carbon is highly electrochemical insert and known for its stable SEI stability. After being coated by carbon, the active LVO‐electrolyte interface turns to a more stable interface, providing a protection for the surface of LVO ,. As for the higher capacity of the LVO/C composite, both the existence of carbon and the large surface of nano‐sized particles may contribute to the high capacity via a surface or interfacial lithium storage mechanism ,.…”