Lithium-ion battery fundamentals and exploration of cathode materials: A review

• Battery energy density is crucial for determining EV driving range, and current Li-ion batteries, despite offering high densities (250 to 693 Wh L⁻¹), still fall short of gasoline, highlighting the need for further advancements and research. • Nickel, manganese, and cobalt play critical roles in NMC cathodes: nickel enhances energy density and EV range, manganese improves safety by preventing thermal runaway, and cobalt boosts thermal stability, though efforts are ongoing to reduce cobalt usage due to cost and ethical concerns. • NMC, LFP, and LMO are top choices for EVs, offering balanced energy density, power density, safety, and overall performance, making them ideal for both EVs and energy storage systems. • Li-Mn-O spinels provide benefits like high ionic conductivity and thermal tolerance but face challenges such as capacity fading and structural instability, which can be mitigated through metal ion doping and acid-resistant coatings. • Emerging battery technologies like solid-state, lithium-sulfur, lithium-air, and magnesium-ion batteries promise significant advancements in energy density, safety, lifespan, and performance but face challenges like dendrite formation, capacity fading, and electrolyte stability. • The future of Li-ion batteries is expected to bring significant advancements in cathode materials, including high-voltage spinels and high-capacity Li-/Mn-rich oxides, integrated with system-level improvements like solid-state electrolytes, crucial for developing next-generation batteries with higher energy densities, faster charging, and longer lifespans. Advances in cathode materials continue to drive the development of safer, more efficient, and sustainable lithium-ion (Li-ion) batteries for various applications, including electric vehicles (EVs) and grid storage. This review article offers insights into key elements—lithium, nickel, manganese, cobalt, and aluminium—within modern battery technology, focusing on their roles and significance in Li-ion batteries. The review paper delves into the materials comprising a Li-ion battery cell, including the cathode, anode, current concentrators, binders, additives, electrolyte, separator, and cell casing, elucidating their roles and characteristics. Additionally, it examines various cathode materials crucial to the performance and safety of Li-ion batteries, such as spinels, lithium metal oxides, and olivines, presenting their distinct advantages and challenges for battery applications. Lithium manganese (Li-Mn-O) spinels, like LiMn 2 O 4 , offer a cost-effective and environmentally friendly option with good thermal stability despite challenges such as capacity fading, which necessitate innovative approaches like dual-doping strategies. Nickel-rich lithium metal oxides like LiNi x Mn y Co 1-x-y O 2 provide high specific energy but face/encounter issues with cobalt reliance and stability, prompting research to reduce cobalt content and increase nickel content. Olivine-based cathode materials, such as lithium iron phosphate (LiFePO4), prioritize safety and stability but exhibit lower energy density, leading to exploration into isomorphous substitutions and nanostructuring to enhance performance. Safety considerations, including thermal management and rigorous testing protocols, are essential to mitigate risks of thermal runaway and short circuits. Thus, this review scrutinizes recent advancements in Li-ion battery cathode materials, delving into strategies aimed at mitigating associated drawbacks and identifying suitable electrode materials based on their electrochemical performance and capacity during operation.