Anodes and Sodium‐Free Cathodes in Sodium Ion Batteries

Abstract

type is cheap but with a rather low energy density and cannot survive many cycles; the latter type has higher energy density and longer cycle life, but is more expensive. [3] Both those secondary batteries suffer from the memory effect, and their use is under serious environmental concerns due to the involvement of the toxic lead and cadmium. [3] Nickel-metal hydride (Ni-MH) batteries can deliver higher energy capacity (the amount of stored energy in per unit mass, usually measured in Wh kg -1 ) and are more environmentally friendly, and from these reasons they used to dominate the market for electrical tools and EV. [4] At present, however, the share of Ni-MH batteries is shrinking, as we have another choice with a much higher energy density, namely lithium ion batteries (LIBs). The energy density of Ni-MH batteries is 60-70 Wh kg -1 , and that of LIBs was about 110 Wh kg -1 when they were commercially launched. [5] In the last decade, the price of LIBs decreased by ≈80% (now reaching <$200 kWh -1 ), and their energy density has been significantly improved (>200 Wh kg -1 ). [6] Other advantages of LIBs include long cycle life, low self-discharge, and absence of the memory effect. Thus far, being cost-effective and performance-competitive, LIBs have conquered the market for various important applications such as mobile phones, portable electronics, and EV.Beyond the state-of-the-art LIBs, efforts of battery researchers are going into following directions. The energy density of gasoline is about 13 kWh kg -1 , a value LIBs would never get close to. [7] It is normal to have "range anxiety" in the transition from petrol vehicles to EV. To eliminate such anxiety and make LIBs more competitive, intensive efforts are being placed into the research of high-capacity electrode materials for LIBs (such as silicon and lithium metal anode) and other battery systems (e.g., lithium-sulfur, lithium-air, and zinc-air batteries). [8] Another important direction is the development of safer batteries, such as aqueous and all-solid-state batteries, as safety concerns on LIBs are mainly related to the use of flammable electrolytes. [9,10] At the same time, the demand for LIBs worldwide is still increasing, and the production of the LIBs is growing rapidly, while the important constituting elements of those batteries, especially lithium and cobalt, are limited in supply. [5] Even though the availability of lithium at the present time may not be the major problem, and the recycling of used LIBs is under consideration, the world is faced with the potential risks in supply chains, as the annual global lithium production has already surpassed 0.085 million tons in 2018, while the total lithium reserve is estimated to be ≈14 million The increase in electricity generation poses growing demands on energy storage systems, thus offering a chance for the success of the reliable and cost-effective energy storage technologies. Sodium ion batteries are emerging as such a technology, which is however not yet mature enough to enter the market. At th...

Nanostructured MoS2‐, SnS2‐, and WS2‐Based Anode Materials for High‐Performance Sodium‐Ion Batteries via Chemical Methods: A Review Article

“…It is important to know that the hardly insertion of Na + therein active anode materials led to the poor cycling performance, slow charging/discharging mechanism, low Coulombic efficiencies etc. [ 24–28 ] So, use of nanostructured materials as an anode offers attractive chemical and physical properties apart from other several advantages like 1) nanoparticles or nanocrystallites being smaller than the bulk materials that makes the distance between electrons and Na + short, which in turn enhances the rate capability and hence power density with the selected anode materials; 2) nanoscale particles being small, which can easily accommodate the strains associated with Na + insertion during the charging and discharging process, which boosts the intercalation of Na + ‐active anode materials that leads to improvement of reversible capacity; and 3) implementing a new design or structure with these small nanoparticles very easily and offering attractive improved properties for energy storage. The knowledge of cutting‐edge nanostructured materials and their synthesis approach is very important for design and fabrication of novel nanostructured materials for various energy‐based applications.…”

Tin‐Containing Graphite for Sodium‐Ion Batteries and Hybrid Capacitors

“…As an alternative to graphite, several micro and nanostructured materials have been proposed for SIBs’ anodes [21–22] . Based on the Na storage mechanism, these materials can be roughly classified into three types 1) carbon‐based materials, sodium titanate (intercalation, insertion/adsorption) 2) metal oxides and sulfides (conversion reaction) 3) high capacity anode materials tin (Sn), Sb, Bi, Si, Ge, and P (alloying /dealloying reaction) [23–24] . Carbons, such as hard/soft carbons and graphene‐based materials are intensively studied as alternatives to graphite [25] .…”

“…[21][22] Based on the Na storage mechanism, these materials can be roughly classified into three types 1) carbon-based materials, sodium titanate (intercalation, insertion/adsorption) 2) metal oxides and sulfides (conversion reaction) 3) high capacity anode materials tin (Sn), Sb, Bi, Si, Ge, and P (alloying /dealloying reaction). [23][24] Carbons, such as hard/soft carbons and graphene-based materials are intensively studied as alternatives to graphite. [25] Graphene or reduced graphene oxide (rGO) anodes deliver specific capacities in the range of 200-250 mAh g À 1 , though they show a very high initial irreversible capacity loss.…”

Optimization Design and Application of Niobium‐Based Materials in Electrochemical Energy Storage

“…However, the instability and poor sustainability of renewable resources make it difficult to be used directly. Therefore, the search for sustainable and efficient energy conversion and storage technologies, especially electrochemical energy storage devices such as lithium-ion battery (LIB), [1] sodium-ion battery (SIB), [2,3] lithium-sulfur battery (Li-S), [4] supercapacitor (SC), [5,6] is one of the development directions of new energy.…”