A review on the key issues for lithium-ion battery management in electric vehicles

Future generations of electric vehicles require driving ranges of at least 300 miles to successfully penetrate the mass consumer market. A significant improvement in the energy density of lithium batteries is mandatory while also maintaining similar or improved rate capability, lifetime, cost, and safety. The vast majority of electric vehicles that will appear on the market in the next 10 years will employ nickel-rich cathode materials, LiNi1–x–yCoxAlyO2 and LiNi1–x–yCoxMnyO2 (x + y < 0.2), in particular. Here, the potential and limitations of these cathode materials are critically compared with reference to realistic target values from the automotive industry. Moreover, we show how future automotive targets can be achieved through fine control of the structural and microstructural properties.

Nickel-Rich Layered Cathode Materials for Automotive Lithium-Ion Batteries: Achievements and Perspectives

Research activities related to the development of negative electrodes for construction of high-performance Li-ion batteries (LIBs) with conventional cathodes such as LiCoO2, LiFePO4, and LiMn2O4 are described. The anode materials are classified in to three main categories, insertion, conversion, and alloying type, based on their reactivity with Li. Although numerous materials have been proposed (i.e., for half-cell assembly), few of them have reached commercial applications, apart from graphite, Li4Ti5O12, Si, and Sn-Co-C. This clearly demonstrates that full-cell studies are desperately needed rather than just characterizing materials in half-cell assemblies. Additionally, the performance of such anodes in practical Li-ion configurations (full-cell) is much more important than merely proposing materials for LIBs. Irreversible capacity loss, huge volume variation, unstable solid electrolyte interface layer formation, and poor cycleability are the main issues for conversion and alloy type anodes. This review addresses how best to circumvent the mentioned issues during the construction of Li-ion cells and the future prospects of such anodes are described in detail.

Research Progress on Negative Electrodes for Practical Li‐Ion Batteries: Beyond Carbonaceous Anodes

Investigating the error sources of the online state of charge estimation methods for lithium-ion batteries in electric vehicles

Rechargeable lithium-ion batteries (LIBs) offer the advantages of having great electrical energy storage and increased continuous and pulsed power output capabilities, which enable their applications in grid energy storage and electric vehicles (EVs). For safety, high power and durability considerations, spinel Li4Ti5O12 is one of the most appealing potential candidate as an anode material for power LIBs due to its excellent cycling stability and thermal stability. However, there are still a number of challenges remaining for Li4Ti5O12 battery applications. Herein, an updated overview of the latest advances in Li4Ti5O12 research is provided and key challenges for its future development (i.e., fast-charging, specific capacity, swelling, interface chemistry, matching cathode and electrolyte as well as batteries design and manufacturing) are highlighted.

Challenges of Spinel Li4Ti5O12 for Lithium‐Ion Battery Industrial Applications

High-power and long-life lithium-ion batteries using lithium titanium oxide anode for automotive and stationary power applications

Laser Welding of Ti-Ni Type Shape Memory Alloy

A spraying robot system in which spraying conditions can be automatically determined correspondingly to the shape of an object to be sprayed. The data on the shape of the object (9) and the data on the spraying material are inputted to a spraying condition determination unit (5) through an input unit (1). A plurality of spraying parameter values of spraying materials are so included in a spraying condition database (3) as to correspond to obtained spraying qualities. A locus calculation unit (4) selects spraying parameter values from the spraying condition database (3) first. Then the locus calculation unit (4) calculates the locus of a spraying gun (14) in accordance with a predetermined program based on the shape data of the object and the selected spraying parameter values. After that, the locus calculation unit (4) judges whether the spraying can be done or not. If it is judged that the spraying can be done, a spraying apparatus (10) performs the spraying in accordance with the selected values of the spraying parameters and the calculated locus of the spraying gun.

Spraying robot system and spraying method wherein spray conditions are determined by using computer

In-situ nitride dispersed TiAl layers were produced from pre-alloyed TiAl powder by a reactive low pressure plasma spraying (RLPPS) process with nitrogen as a powder carrier gas. RLPPS TiAl layers had fine grain structures whose grain sizes ranged from approximately 50 to 150 nm and included ternary nitride, Ti2AlN. The volume fraction of nitride decreased with increasing spray distance from 300 to 600 mm, whereas no significant change in the nitrogen contents of sprayed layers occurred. Nitride precipitation may be suppressed by rapid cooling in sprayed layers formed at a long spray distance. The maximum hardness of 709 Hv was obtained at room temperature in a RLPPS TiAl layer formed with an appropriate spray distance, 400 mm in the present case. However, a RLPPS TiAl layer formed with shorter spray distance, 300 mm, was superior in hardness at temperatures above 873 K because of higher volume fraction of nitride. Although the hardness values of RLPPS TiAl layers dropped to approximately 450 Hv after being exposed to a temperature of 1273 K for 24 h, the hardness value was higher by approximately 100 Hv than that of a LPPS TiAl layer formed with argon carrier gas. This is caused by effects of both the fine grain structure and nitride precipitation hardening.

Properties of in-situ nitride reinforced titanium-aluminide layers formed by reactive low pressure plasma spraying with nitrogen gas

TiAl alloyed powder was sprayed onto a substrate surface by the low pressure plasma spraying (LPPS) process. The microstructure and properties of sprayed TiAl layers were examined and compared with those of a TiAl bulk plate. As-sprayed TiAl layer consisted of γ fine grains whose average grain size was 90 nm including a small amount of α2. The sprayed layer had a hardness value of 589 Hv at room temperature and above 400 Hv even at 1073 K. Although the hardness value dropped to 225 Hv at 1173 K, it was still comparable to that of a TiAl bulk plate at room temperature. The microstructure and mechanical properties of the sprayed TiAl layers changed only slightly when exposed to a high temperature of up to 973 K for 48 h. Although the hardness values of sprayed TiAl layers decreased to 350 Hv when annealed at 1273 K for 24 h and more because of the occurrence of grain growth, the hardness values were significantly higher than that of a TiAl bulk plate. Tensile strength above 400 MPa, which was almost equal to that of a TiAl bulk plate, was obtained for sprayed TiAl layers both in as-sprayed and annealed (at 1273 K for 24 h) conditions. Therefore, sprayed TiAl layers were found to be a feasible hardfacing layer at elevated temperatures.

Keizoh Honda

Papers

High-power and long-life lithium-ion batteries using lithium titanium oxide anode for automotive and stationary power applications

Laser Welding of Ti-Ni Type Shape Memory Alloy

Spraying robot system and spraying method wherein spray conditions are determined by using computer

Properties of in-situ nitride reinforced titanium-aluminide layers formed by reactive low pressure plasma spraying with nitrogen gas

Properties of titanmm-aluminide layer formed by low pressure plasma spraying