A Long‐Cycle‐Life Lithium–CO₂ Battery with Carbon Neutrality

Abstract

Lithium-CO 2 batteries are attractive energy storage systems for fulfilling the demand of future large-scale applications such as electric vehicles due to their high specific energy density compared to lithium-ion batteries. However, a major challenge with Li-CO 2 batteries is attaining reversible formation and decomposition of the Li 2 CO 3 and carbon discharge products, along with a lack of mechanistic understanding of the associated charge and discharge reaction mechanisms. In this study, we developed a fully reversible Li-CO 2 battery with overall carbon neutrality using molybdenum disulfide nanoflakes as a cathode catalyst combined with an ionic liquid and dimethyl sulfoxide hybrid electrolyte. This combination of materials produces a multicomponent composite (Li 2 CO 3 /C) product rather than formation of separated carbon and Li 2 CO 3 nanoparticles. The battery shows a superior long cycle life of 500 for a fixed 500 mAh/g capacity per cycle, which is by far the best cycling stability reported in Li-CO 2 batteries, respectively. The long cycle life demonstrates for the first time that covalent CO bond making and breaking chemical transformations can be used in energy storage systems, in addition to the widely studied alkali metal (Li, Na, K)-oxygen ionic-bond making and breaking transformations. Theoretical calculations are used to deduce a mechanism for the reversible discharge/charge processes and explain how the carbon interface with Li 2 CO 3 provides the electronic conduction needed for the oxidation of Li 2 CO 3 , as well as the carbon to generate the CO 2 on charge. The achievement of a reversible, long cycle life Li-CO 2 battery opens the way for use of CO 2 in advanced energy storage systems. Lithium-ion batteries are widely used as electrochemical energy storage systems for consumer electronics [1] ; however, technologies with higher specific energy are needed for electrified transportation applications [2]. Therefore, beyond Li-ion battery chemistries such as rechargeable Li-O 2 batteries have recently garnered much attention This article is protected by copyright. All rights reserved. 3 due to their higher theoretical energy density [3,4]. Li-O 2 batteries generally have limited cyclability, though several studies have reported new concepts that have achieved long cycle life [5,6]. Although far less studied, the Li-CO 2 battery is another beyond Li-ion technology with a theoretical energy density of 1876 Wh/kg [7,8] , far exceeding that of Li-ion batteries (~265 Wh/kg). This type of battery involves CO 2 reduction and evolution reactions during discharge and charge, respectively, on the surface of a porous cathode with an electrolyte based on lithium salts.

Light/Electricity Energy Conversion and Storage for a Hierarchical Porous In2S3@CNT/SS Cathode towards a Flexible Li‐CO2 Battery

“…However, the reduction of CO 2 into CO 2 .− requires a highly negative potential (−2.21 V vs. SCE), owing to the stability of CO 2 molecule. For catalysts, this still results in the sluggish kinetics of CDRR process, leading to huge polarization and limited energy efficiency . In contrast, it seems that a different reaction mechanism occurs in the photoinduced Li‐CO 2 cell with ICS cathode.…”

“…SCE), [19] owing to the stability of CO 2 molecule.F or catalysts,this still results in the sluggish kinetics of CDRR process,l eading to huge polarization and limited energy efficiency. [20] In contrast, it seems that ad ifferent reaction mechanism occurs in the photoinduced Li-CO 2 cell with ICS cathode.According to the lightassisted discharge process mentioned above,t he photoexcitation of ICS by the photons produces separated e À hv -h + pairs [Eq. (1)].T hen, e À hv transfers to the surface and reduces In 3+ to form In + ,because the redox potential (À0.4 Vvs.…”

Nano Polymorphism‐Enabled Redox Electrodes for Rechargeable Batteries

“…Among these metal-air batteries, Li-CO 2 batteries have received significant attention because they reuse CO 2 as a renewable energy carrier and reduce the anthropogenic CO 2 emissions. To date, a wide range of electrocatalysts, such as noble metal nanoparticles, [185] metal-organic frameworks, [186] covalent organic frameworks, [187] metal sulfides, [188,189] metal oxides, [190][191][192][193] metal carbides, [194][195][196] metal phosphides, [197] graphene/CNTs/carbon, [198][199][200][201][202] metal polyphthalocyanines, [203] and metal/carbon hybrids, [204][205][206][207][208][209][210] have been investigated for activating stabilized CO 2 , manipulating the discharge product distribution, and promoting reversibility in Li-CO 2 batteries. The main discharge products of the reduction process in Li-CO 2 batteries include Li 2 CO 3 and carbon.…”

Metal–CO2 Batteries at the Crossroad to Practical Energy Storage and CO2 Recycle

“…Catalytic cathodes based on transition metal or metal‐free carbon materials have also enabled the achievement of the Li/Na‐CO 2 system with lower charge voltages and prolonged cyclability, as listed in Table . Recent theoretical calculations further revealed that with MoS 2 nanoflakes as the cathode in catalyzing the generation of carbonate and carbon composite, the electronic conduction provided by the amorphous carbon interface with insulated carbonate would facilitate the cooxidation of carbon and carbonate, leading to decreased charge voltages …”