Energy storage using batteries offers a solution to the intermittent nature of energy production from renewable sources; however, such technology must be sustainable. This Review discusses battery development from a sustainability perspective, considering the energy and environmental costs of state-of-the-art Li-ion batteries and the design of new systems beyond Li-ion. Images: batteries, car, globe: © iStock/Thinkstock.

Towards greener and more sustainable batteries for electrical energy storage

Research Development on Sodium-Ion Batteries

The status of ambient temperature sodium ion batteries is reviewed in light of recent developments in anode, electrolyte and cathode materials. These devices, although early in their stage of development, are promising for large-scale grid storage applications due to the abundance and very low cost of sodium-containing precursors used to make the components. The engineering knowledge developed recently for highly successful Li ion batteries can be leveraged to ensure rapid progress in this area, although different electrode materials and electrolytes will be required for dual intercalation systems based on sodium. In particular, new anode materials need to be identified, since the graphite anode, commonly used in lithium systems, does not intercalate sodium to any appreciable extent. A wider array of choices is available for cathodes, including high performance layered transition metal oxides and polyanionic compounds. Recent developments in electrodes are encouraging, but a great deal of research is necessary, particularly in new electrolytes, and the understanding of the SEI films. The engineering modeling calculations of Na-ion battery energy density indicate that 210 Wh kg−1 in gravimetric energy is possible for Na-ion batteries compared to existing Li-ion technology if a cathode capacity of 200 mAh g−1 and a 500 mAh g−1 anode can be discovered with an average cell potential of 3.3 V.

Sodium‐Ion Batteries

Electrolytes and interphases in Li-ion batteries and beyond.

Energy production and storage technologies have attracted a great deal of attention for day-to-day applications. In recent decades, advances in lithium-ion battery (LIB) technology have improved living conditions around the globe. LIBs are used in most mobile electronic devices as well as in zero-emission electronic vehicles. However, there are increasing concerns regarding load leveling of renewable energy sources and the smart grid as well as the sustainability of lithium sources due to their limited availability and consequent expected price increase. Therefore, whether LIBs alone can satisfy the rising demand for small- and/or mid-to-large-format energy storage applications remains unclear. To mitigate these issues, recent research has focused on alternative energy storage systems. Sodium-ion batteries (SIBs) are considered as the best candidate power sources because sodium is widely available and exhibits similar chemistry to that of LIBs; therefore, SIBs are promising next-generation alternatives. Recently, sodiated layer transition metal oxides, phosphates and organic compounds have been introduced as cathode materials for SIBs. Simultaneously, recent developments have been facilitated by the use of select carbonaceous materials, transition metal oxides (or sulfides), and intermetallic and organic compounds as anodes for SIBs. Apart from electrode materials, suitable electrolytes, additives, and binders are equally important for the development of practical SIBs. Despite developments in electrode materials and other components, there remain several challenges, including cell design and electrode balancing, in the application of sodium ion cells. In this article, we summarize and discuss current research on materials and propose future directions for SIBs. This will provide important insights into scientific and practical issues in the development of SIBs.

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Sodium-ion batteries: present and future

Layered structure NaCrO2 (R-3m) was successfully synthesized by solid state reaction. The electrochemical performance of NaCrO2 as a positive electrode material for sodium-ion batteries was tested at room temperature using two-electrode coin cells with NaClO4/PC electrolyte. NaCrO2 delivered a reversible capacity of 110 mAh/g during the first charge and had good cyclability. The reaction between deintercalated NaxCrO2 (~Na0.5CrO2) and ethylene carbonate/diethyl carbonate solvent was studied using Accelerating Rate Calorimetry (ARC). The results were compared to analogous results for Li0.5CoO2 and Li0FePO4 under the same conditions. Na0.5CrO2 showed an unexpected excellent thermal stability in solvent with no heat release in the ARC test temperature range. An X-ray diffraction study showed that Na0.5CrO2 decomposes to NaCrO2 and P3-type layered structure CrO2-δ with minimal oxygen release during the ARC tests, which explains the lack of exothermic behavior.

https://iopscience.iop.org/article/10.1149/2.002201esl/pdf

NaCrO2 is a Fundamentally Safe Positive Electrode Material for Sodium-Ion Batteries with Liquid Electrolytes

Introduction Sodium-ion batteries are now receiving attention due to the low cost and abundance of sodium, compared to lithium [1]. Sodium cannot intercalate into graphitized carbon so nanoporous carbon is currently the most attractive negative electrode material for sodium-ion batteries [2]. In this work, the reactivity of sodium inserted hard carbon (called Na/HC below) in different solvents (EC, DEC, DMC, EC: DEC and EC: DMC) and electrolytes (NaPF6 EC: DEC and NaPF6 EC: DMC) was studied by Accelerating Rate Calorimeter (ARC) and X-ray diffraction was used to analyse the products of Na/HC after all ARC experiments.

http://jes.ecsdl.org/content/159/5/A515.full.pdf

Study of the Reactivity of Na/Hard Carbon with Different Solvents and Electrolytes

http://ma.ecsdl.org/content/MA2011-02/8/428.full.pdf

Study of the Reactivity of Na/Hard Carbon in Different Solvents and Electrolytes

The effects of vinylene carbonate (VC), fluoroethylene carbonate (FEC) and vinyl ethylene carbonate (VEC) electrolyte additives on electrode/electrolyte reactivity at elevated temperatures were investigated using accelerating rate calorimetry (ARC). Li(Ni1/3Mn1/3Co1/3)O2 (NMC) and graphite (mesocarbon microbeads (MCMB)) were utilized as the electrodes and 1.0 M LiPF6 in ethylene carbonate (EC):diethyl carbonate (DEC) (1:2 by volume) was chosen as control electrolyte. Adding 10 wt% VC, FEC or VEC to the electrolyte does not significantly impact the reactivity of delithiated NMC compared to the control electrolyte. However, the three additives affected the reactivity between lithiated graphite and electrolyte at elevated temperatures in different ways. Adding VC (up to 10%) reduces the reactivity between lithiated graphite and electrolyte below about 200°C, adding VEC does not affect the reactivity at all, while adding over 5 wt% FEC causes a small exotherm beginning as low as 50°C. After this small exotherm completes, electrolytes with 10 wt% FEC show more reactivity with lithiated graphite than control electrolyte above 130°C. These results give a head to head comparison of the reactivity of electrolytes containing VC, VEC or FEC with charged electrode materials at elevated temperatures and show that the use of VC and VC at levels of 10 wt% or less should not compromise the safety of Li-ion batteries.

The Impact of Vinylene Carbonate, Fluoroethylene Carbonate and Vinyl Ethylene Carbonate Electrolyte Additives on Electrode/Electrolyte Reactivity Studied Using Accelerating Rate Calorimetry

Li[Li 1/9 Ni 1/3 Mn 5/9 ]O 2 , Li[Li 1/5 Ni 1/5 Mn 3/5 ]O 2 , LiNi 0.5 Mn 1.5 O 4 , and LiNi 2/3 Mn 1/3 O 2 were prepared from appropriate coprecipitated hydroxides. The hydroxides were heated with lithium hydroxide in air to make the lithium transition metal oxides. "Head to head" comparisons among these materials were made by X-ray diffraction, scanning electron microscopy, electrochemical tests, and accelerating rate calorimetry, which suggest that all of them have one or more remaining problem to overcome before they can be used widely. We encourage the needed research.

http://jes.ecsdl.org/content/158/2/A187.full.pdf

Comparison of Li [ Li1 ∕ 9Ni1 ∕ 3Mn5 ∕ 9 ] O2, Li [ Li1 ∕ 5Ni1 ∕ 5Mn3 ∕ 5 ] O2, LiNi0.5Mn1.5O4, and LiNi2 ∕ 3Mn1 ∕ 3O2 as High Voltage Positive Electrode Materials

Xin Xia

Papers

NaCrO2 is a Fundamentally Safe Positive Electrode Material for Sodium-Ion Batteries with Liquid Electrolytes

Study of the Reactivity of Na/Hard Carbon with Different Solvents and Electrolytes

Study of the Reactivity of Na/Hard Carbon in Different Solvents and Electrolytes

The Impact of Vinylene Carbonate, Fluoroethylene Carbonate and Vinyl Ethylene Carbonate Electrolyte Additives on Electrode/Electrolyte Reactivity Studied Using Accelerating Rate Calorimetry

Comparison of Li [ Li1 ∕ 9Ni1 ∕ 3Mn5 ∕ 9 ] O2, Li [ Li1 ∕ 5Ni1 ∕ 5Mn3 ∕ 5 ] O2, LiNi0.5Mn1.5O4, and LiNi2 ∕ 3Mn1 ∕ 3O2 as High Voltage Positive Electrode Materials