High Pressure Rapid Synthesis of LiCrTiO₄ with Oxygen Vacancy for High Rate Lithium‐Ion Battery Anodes

Abstract

Among multitudinous recommendations, Li 4 Ti 5 O 12 (LTO) is considered as a promising anode material owing to its steady operating voltage platform at 1.55 V (versus Li/Li + ), which can prevent the growth of lithium dendrites. [5] In addition, the zero-strain insertion characteristic makes it possess excellent cycle performance and stability. [6,7] Meanwhile, the operational voltage of LTO can also prevent the decomposition of most electrolyte. [8] However, the inherent low conductivity (<10 −13 S cm −1 ) [9] and poor ion diffusion coefficient (10 −13 cm 2 s −1 ), [10] limit its large-scale application. In order to solve this problem, researchers have been introduced Cr 3+ into the lattice of LTO, which can not only reduce the average working potential to 1.5 V (versus Li/Li + ), but effectively improve the electrochemical performance. [11] For example, Song et al. reported LCTO formed by doping Cr 3+ into LTO qualified higher capacity especially at high rate, and better ionic diffusivity. [12] Wu et al. found that Cr 3+ doped LCTO exhibits exceptional cycling stability at high current densities. [13] Although the theoretical specific capacity of LCTO is only 157 mAh g −1 , the lower lithium content has advantages in terms of lithium resource requirements. [14] More importantly, the conductivity (10 −6 S cm −1 ) and lithium-ion diffusion coefficient (10 −8 -10 −9 cm 2 s −1 ) have been significantly enhanced compared with LTO. [15,16] Transition metal oxides are elementally abundant and inexpensive, and exhibit excellent stability in redox environments. [17] Therefore, LCTO has become a promising anode material for lithium-ion batteries with superior industrialization potential.In order to realize the industrialization development as soon as possible, a great deal of synthetic technologies have been explored and reported, such as solid-state reaction, [14,18] solgel, [19] electro-spinning, [20] acrylic acid polymerization [21] and sonochemistry. [22] The existing research on LCTO mainly concentrates on two aspects, one effective approach is to increase the conductivity of materials, such as coating and composite carbon materials, [23] or ion doping, [16] which can further ameliorate the electrochemical performance. However, the coating of carbon material will reduce the tap density, so as to reduce the energy density, and there is also a current lag phenomenon at high rate. Another approach is forming nanostructures, [24] which can provide an enormous specific surface area and Lithium-ion battery based on LiCrTiO 4 (LCTO) is considered to be a promising anode material, as they provide higher safety and durability beyond than that of graphite electrode. However, the applications of this transformative technology demand improved inherent electrical conductivity of LCTO as well as a simple and rapid synthetic route. Here, LCTO with oxygen vacancies (OVs) is fabricated using high-pressure synthesis technology in only 40 min. The optimal synthesis pressure is 0.8 GPa (LCTO-0.8). The reversible capacity of LCTO-0.8 at...

Designing strategies of advanced electrode materials for high-rate rechargeable batteries

“…(f) Electrical conductivity comparison of different processing pressure times. 119 Copyright 2022, Wiley. (g) STEM and EELS mapping images (inset) of LTO-60% ethanol microspheres at 60% SOC, where the green points represent the Li + ions and red points represent the LTO nanograins.…”

“…At 5C, the capacity was 110 mA h g −1 , higher than that of the pristine LCTO by 77%. 119 The poor conductivity can be greatly boosted by coating with conductive materials, but achieving uniformity of the coating is required. 120,121 Combination with carbon-based materials is one of the most popular candidate methods to boost the conductivity.…”

Through-hole graphite made from waste graphite for high-rate lithium-ion battery anodes

“…31 Moreover, the R ct of MDSG-480 is 8.6 times smaller than that of NFG, indicating that the MDSG-480 electrode has better electron transfer capability than NFG. 14…”

“…1,4 In this context, how to supply low-cost anode materials with high-performance is a core issue in the development of LIBs. 5 Based on this, most of the existing research focuses on nding low-cost materials, such as biomass carbon, [6][7][8][9][10][11] or costfor-performance approach [12][13][14][15][16] to replace the graphite used in commercial equipment. However, most of these materials are still under academic research and far from industrial production and applications.…”

“…Based on this, most of the existing research focuses on finding low-cost materials, such as biomass carbon, 6–11 or cost-for-performance approach 12–16 to replace the graphite used in commercial equipment. However, most of these materials are still under academic research and far from industrial production and applications.…”