Manganites of transition and/or post-transition metals, AMn₂O₄ (where A was Co, Ni or Zn), were synthesized by a simple and easily scalable co-precipitation route and were evaluated as anode materials for Li-ion batteries. The obtained powders were characterized by SEM, TEM, and XRD techniques. Battery cycling showed that ZnMn₂O₄ exhibited the best performance (discharge capacity, cycling, and rate capability) compared to the two other manganites and their corresponding simple oxides. Further studies on the effect of different sintering temperatures (from 400 to 1000 °C) on particle size were performed, and it is found that the size of the particles had a significant effect on the performance of the batteries. The optimum particle size for ZnMn₂O₄ is found to be 75–150 nm. In addition, the use of water-soluble and environmentally friendly binders, such as lithium and sodium salts of carboxymethlycellulose, greatly improved the performance of the batteries compared to the conventional binder, PVDF. Finally, ZnMn₂O₄ powder sintered at 800 °C (<150 nm) and the use of the in-house synthesized lithium salt of carboxymethlycellulose (LiCMC) binder gave the best battery performance: a capacity of 690 mA h g⁻¹ (3450 mA h mL⁻¹) at C/10, along with good rate capability and excellent capacity retention (88%).

Adiponitrile, <mml:math display="inline"><mml:mrow><mml:mi mathvariant="normal">C</mml:mi><mml:mi mathvariant="normal">N</mml:mi><mml:msub><mml:mrow><mml:mo>[</mml:mo><mml:mi mathvariant="normal">C</mml:mi><mml:msub><mml:mi mathvariant="normal">H</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>]</mml:mo></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub><mml:mi mathvariant="normal">C</mml:mi><mml:mi mathvariant="normal">N</mml:mi></mml:mrow></mml:math>CN[CH2]4CN , ADN, was evaluated as both a solvent and cosolvent in safer and more electrochemically stable electrolytes suitable for high energy and power density Li-ion batteries. An electrochemical investigation of its electrolyte solution with the <mml:math display="inline"><mml:mrow><mml:mi mathvariant="normal">Li</mml:mi><mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi mathvariant="normal">C</mml:mi><mml:msub><mml:mi mathvariant="normal">F</mml:mi><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub><mml:mi mathvariant="normal">S</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mi mathvariant="normal">N</mml:mi></mml:mrow></mml:math>Li(CF3SO2)2N , LiTFSI, salt showed a wide electrochemical window of <mml:math display="inline"><mml:mrow><mml:mn>6</mml:mn><mml:mspace width="0.3em"></mml:mspace><mml:mi mathvariant="normal">V</mml:mi></mml:mrow></mml:math>6V vs <mml:math display="inline"><mml:mrow><mml:msup><mml:mi mathvariant="normal">Li</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>∕</mml:mo><mml:mi mathvariant="normal">Li</mml:mi></mml:mrow></mml:math>Li+∕Li . The high melting point and the incompatibility of ADN with graphite anode required the use of ethylene carbonate (EC) as a cosolvent. The resultant EC:ADN electrolyte solutions showed ionic conductivities reaching <mml:math display="inline"><mml:mrow><mml:mn>3.4</mml:mn><mml:mspace width="0.3em"></mml:mspace><mml:mi>mS</mml:mi><mml:mo>∕</mml:mo><mml:mi>cm</mml:mi></mml:mrow></mml:math>3.4mS∕cm , viscosities of <mml:math display="inline"><mml:mrow><mml:mn>9.2</mml:mn><mml:mspace width="0.3em"></mml:mspace><mml:mi>cP</mml:mi></mml:mrow></mml:math>9.2cP , and an improved resistance to aluminum corrosion up to <mml:math display="inline"><mml:mrow><mml:mn>4.4</mml:mn><mml:mspace width="0.3em"></mml:mspace><mml:mi mathvariant="normal">V</mml:mi></mml:mrow></mml:math>4.4V , all at <mml:math display="inline"><mml:mrow><mml:mn>20</mml:mn><mml:mo>°</mml:mo><mml:mi mathvariant="normal">C</mml:mi></mml:mrow></mml:math>20°C . Li-ion batteries incorporating graphite/ <mml:math display="inline"><mml:mrow><mml:mi mathvariant="normal">Li</mml:mi><mml:mi mathvariant="normal">Co</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>LiCoO2 electrodes were assembled using EC:ADN electrolyte mixture containing <mml:math display="inline"><mml:mrow><mml:mn>1</mml:mn><mml:mspace width="0.3em"></mml:mspace><mml:mi mathvariant="normal">M</mml:mi></mml:mrow></mml:math>1M LiTFSI and <mml:math display="inline"><mml:mrow><mml:mn>0.1</mml:mn><mml:mspace width="0.3em"></mml:mspace><mml:mi mathvariant="normal">M</mml:mi></mml:mrow></mml:math>0.1M LiBOB as a cosalt, and discharge capacities of <mml:math display="inline"><mml:mrow><mml:mn>108</mml:mn><mml:mspace width="0.3em"></mml:mspace><mml:mi>mAh</mml:mi><mml:mo>∕</mml:mo><mml:mi mathvariant="normal">g</mml:mi></mml:mrow></mml:math>108mAh∕g with very good capacity retention were obtained. AC impedance spectra of the batteries recorded as a function of charging and cycling indicated the presence of a stable solid electrolyte interface.

As the electrification of the transportation industry is accelerating, the energy storage markets are trying to secure more reliable and environmentally benign materials. Advanced materials are the key performance enablers of batteries as well as a key element determining the cost structure, environmental impact, and recyclability of battery cells. In this review, we analyzed the state-of-the-art cell chemistries and active electrode and electrolyte materials for electric vehicles batteries, which we believe will dominate the battery chemistry landscape in the next decade. We believe that major breakthroughs and innovations in electrode materials such as high-nickel cathodes and silicon and metallic lithium anodes, along with novel liquid electrolyte formulations and solid-state electrolytes, will significantly improve the specific capacity of lithium batteries and reduce their cost, leading to accelerated mass-market penetration of EVs.

High voltage spinel has been synthesized by a modified Pechini sol–gel method and has been characterized by transmission electron microscopy, X-ray diffraction (XRD), and electrochemical methods. The synthesized materials are porous structures of nanosized crystallites ranging in size from 21 to over 400 nm depending on the sintering temperature used. The XRD patterns of the materials were assigned to the disordered spinel structure of the space group . The Li-ion batteries assembled using the synthesized cathode materials showed significant capacity fade for samples sintered at , while for those sintered at the capacity fade was low. Impedance spectroscopy, Fourier transform IR spectroscopy, and X-ray photoelectron spectroscopy were used to determine the compositions of the cathode electrolyte interphase (CEI). Impedance spectroscopy confirmed the spontaneous formation of the CEI on and that its thickness grows on cycling. After more than 100 cycles, it is found that the CEI film is composed of polycarbonates, polyether, LiF, and salts. The composition of the organic layer was the same regardless of the capacity fade.

The surface layer (Cathode-Electrolyte Interface; CEI) on LiMn_1.5Ni_0.5O₄, a promising, high voltage positive electrode for Li-ion batteries, was studied by XPS, AC impedance spectroscopy and FTIR spectroscopy. Half cells and full cells with LiMn_1.5Ni_0.5O₄as positive electrode material and Li₄Ti₅O₁₂as a negative electrode material were assembled in conventional carbonate-based electrolytes with LiPF₆or LiBF₄as the salt, and the effect of cycling at different operating conditions (short and long storage time, state of charge and temperature) on the surface layer composition was assessed. Capacities reaching near the theoretical value of 140 mAh g₋₁were obtained in half cells cycled at C/2 and room temperature, with 85% of the capacity being retained after 100 cycles. Cycling at 60°C leads to a decrease in capacity and coulombic efficiency. The surface analysis by XPS revealed that the CEI is composed of inorganic species such as LiF and Li_xPF_yO_zor Li_xBF_yO_zas well as organic species such as polyethers and carbonates. Generally, it was found that cycling or storing the material at 60°C with an electrolyte using LiPF₆as a salt yield more organic species and less LiF at the surface than the one with LiBF₄.

In this study, silicon–graphite composites were prepared and investigated as anode materials for Li-ion batteries with small amounts of silicon and different binders. The silicon powders were prepared by ball-milling crystalline silicon for 100 h and 200 h. After 200 h, an average silicon particle size of 0.73 μm was obtained and XRD measurements confirmed the formation of an amorphous powder embedded within nanocrystalline regions. XPS analysis of the silicon samples showed that silicon particles were covered with a native silicon oxide layer that grows during ball-milling. Battery cycling of the silicon powders in half cells showed that the powder ball milled for 200 h gave the lowest first-cycle irreversible capacity and the highest reversible capacity reaching over 500 mA h g⁻¹ after 50 cycles at C/12. Composites were made using graphite and only 5 wt% silicon powders. The silicon was found to be uniformly dispersed into the composites as evidenced by X-ray mapping and SEM. When tested in half cells using different binders, it was found that the polyetherimide binder showed the highest capacity reaching 514 mA h g⁻¹ after 350 cycles at C/12, which is 1.6 times greater than commercial graphite anode. High rate cycling showed good capacity retention reaching half the capacity at 5 C.