A redox-active organic cation for safer metallic lithium-based batteries

TY - JOUR

T1 - A redox-active organic cation for safer metallic lithium-based batteries

AU - Ji, Weixiao

AU - Huang, He

AU - Zheng, Dong

AU - Zhang, Xiaoxiao

AU - Ding, Tianyao

AU - Lambert, Tristan H.

AU - Qu, Deyang

N1 - Publisher Copyright: © 2020 Elsevier B.V.

PY - 2020/11

Y1 - 2020/11

N2 - Safety concerns have severely impeded the practical application of high-energy-density lithium-based batteries. Dendrite growth and overcharging can lead to particularly catastrophic thermal failure. Here we report an organic cation, trisaminocyclopropenium (TAC), as a bi-functional electrolyte additive to suppress dendrite growth and offer reversible overcharge protection for metallic lithium-based batteries. During the Li plating process, TAC cations with aliphatic chains can form a positively charged electrostatic shield around Li protrusions, repelling the approaching Li+ and thereby attaining a more uniform plating. A two times longer cycle life of 300 h at 1 mA cm−2 is achieved in a Li|Li symmetric cell in comparison with the control. During the overcharging process, the redox-active TAC can repeatedly shuttle between two electrodes, maintaining the cell voltage within a safe value. A solid protection of 117 cycles (~1640 h) at 0.2 C with a 100% overcharge is achieved in a LiFePO4/Li4Ti5O12 cell. This study sheds fresh light on the ability of organic cations to build safer batteries.

AB - Safety concerns have severely impeded the practical application of high-energy-density lithium-based batteries. Dendrite growth and overcharging can lead to particularly catastrophic thermal failure. Here we report an organic cation, trisaminocyclopropenium (TAC), as a bi-functional electrolyte additive to suppress dendrite growth and offer reversible overcharge protection for metallic lithium-based batteries. During the Li plating process, TAC cations with aliphatic chains can form a positively charged electrostatic shield around Li protrusions, repelling the approaching Li+ and thereby attaining a more uniform plating. A two times longer cycle life of 300 h at 1 mA cm−2 is achieved in a Li|Li symmetric cell in comparison with the control. During the overcharging process, the redox-active TAC can repeatedly shuttle between two electrodes, maintaining the cell voltage within a safe value. A solid protection of 117 cycles (~1640 h) at 0.2 C with a 100% overcharge is achieved in a LiFePO4/Li4Ti5O12 cell. This study sheds fresh light on the ability of organic cations to build safer batteries.

KW - Dendrite suppression

KW - Electrolyte additive

KW - Metallic lithium-based batteries

KW - Overcharge protection

KW - Trisaminocyclopropenium cation

UR - https://www.scopus.com/pages/publications/85088916631

U2 - 10.1016/j.ensm.2020.07.038

DO - 10.1016/j.ensm.2020.07.038

M3 - Article

AN - SCOPUS:85088916631

SN - 2405-8297

VL - 32

SP - 185

EP - 190

JO - Energy Storage Materials

JF - Energy Storage Materials

ER -