High-performance metal–iodine batteries enabled by a bifunctional dendrite-free Li–Na alloy anode

Abstract

Rechargeable aprotic alkali metal (Li and Na)-iodine (AM-I2) batteries with high theoretical capacity and specific energy density have emerged as one of the promising energy storage technologies. However, their application...

Liquid‐Phase Exfoliated Few‐Layer Iodine Nanosheets for High‐Rate Lithium‐Iodine Batteries

“…(The specific capacity here is calculated based on the total mass, and the rest based on the mass of FLINs.) There are two pairs of reversible redox peaks in the CV curves (Figure 3b), corresponding to the reduction of I 2 reduced to I 3 − (3.51 V), and subsequent reduce to I − (2.98 V) and the oxidation of I − oxide to I 3 − (3.08 V), then to I 2 (3.64 V) [11,17,18] . In addition, the first 2.2 V cathodic peak in the first cycle could be ascribed to forming solid‐electrolyte inter phase film [38,39] .…”

“…There are two pairs of reversible redox peaks in the CV curves (Figure 3b), corresponding to the reduction of I 2 reduced to I 3 À (3.51 V), and subsequent reduce to I À (2.98 V) and the oxidation of I À oxide to I 3 À (3.08 V), then to I 2 (3.64 V). [11,17,18] In addition, the first 2.2 V cathodic peak in the first cycle could be ascribed to forming solid-electrolyte inter phase film. [38,39] The CV curves (Figure 3b) almost overlap except for the first two cycles, indicating the stable and superior reversibility between I 2 and LiI.…”

“…[6][7][8][9] Moreover, high solubility of iodine in aprotic electrolyte results in fast capacity deterioration, "shuttle effect" (the dissolved iodine diffuses to the surface of lithium metal anode and react with lithium) as well as low columbic efficiency. [10,11] To address these issues, great efforts have been made to understand and improve the performance of iodine cathode. [12,13] Inspired by the "shuttle effect" solution of sulfur, [14,15] various carbon hosts, such as carbon cloth, [10] graphene, [16,17] CNT, [18] 3D porous carbon, [19] hollow carbon spheres [6] and hierarchically porous carbon matrix, [20] have been fabricated, which are conducive to anchoring the iodine and enhancing the conductivity.…”

“…However, low electrical conductivity of iodine leads to sluggish kinetics and poor rate capability [6–9] . Moreover, high solubility of iodine in aprotic electrolyte results in fast capacity deterioration, “shuttle effect” (the dissolved iodine diffuses to the surface of lithium metal anode and react with lithium) as well as low columbic efficiency [10,11] …”

Highly Thermally/Electrochemically Stable I−/I3−Bonded Organic Salts with High I Content for Long‐Life Li–I2Batteries

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chemistry to achieve high energy and power densities, in which their novel chemical processes have attracted considerable attention. [1][2][3][4][5][6][7][8] So far, diversified metal-halogen batteries such as zinc-iodine, [9][10][11][12] zinc-bromine, [13,14,15] lithium-iodine, [16][17][18] lithium-bromine/ chlorine, [2,19,20] sodium-iodine, [21,22] magnesium-iodine [23,24] and other metal-halogen batteries [25][26][27][28][29] have been developed owing to the high compatibility of halogen cathodes with metal anodes. Among the emerging energy storage systems, rechargeable non-aqueous lithium iodine (Li-I 2 ) batteries are promising next-generation technologies featuring desired energy density, sustainability and affordability due to the earth-abundant (50-60 µg iodine L −1 in the ocean), highly reversible iodine cathode, as well as high-capacity and low-electrode-potential (−3.04 V versus standard hydrogen electrode) of Li metal anode.

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