Proof-of-Concept Molten Lithium–Selenium Battery

Abstract

Most space missions utilize energy storage, such as a rechargeable battery onboard the spacecraft. Therefore, a continuing evolution of battery performance can benefit a wide gamut of space science missions conducted or planned by NASA and worldwide space agencies. Venus presents the most significant challenge to energy storage systems due to a combination of high temperature (465 °C) and the presence of corrosive gases (CO 2 , CO, SO 2 , and N 2 ). On a NASA-funded project, a high-temperature (465 °C) lithium−selenium (Li∥Se) battery consisting of an anode of molten Li, a lithium-ion conducting ceramic electrolyte (garnet-type Li 6.4 Al 0.2 La 3 Zr 2 O 12 , LLZO), and a cathode of Se have been conceptualized. The proof-of-concept Li∥Se cells were built using baseline cell electrodes, electrolytes, and cell design. The fabricated Li∥Se cell was tested in an in-house built cell holder placed in an argon-filled glovebox. Electrochemical testing includes time-dependent open-circuit voltage measurements across a wide temperature range (230−500 °C) and electrochemical cycling at multiple current rates at 465 °C. Further cell components and design optimization will enable higher current charge−discharge and a longer battery life span over a wide temperature range. In addition, the use of high-energy electrodes will encourage longduration and safe Venus surface exploration.

Electrode/electrolyte interphases in high-temperature batteries: a review

“…Recently some new concepts of molten lithium metal batteries have been created, which consists of liquid lithium anodes, alloy (Se Sn, Bi, and Pb) liquid cathodes and lithium ion conductors as solid electrolytes. For example, Ashish Gogia et al 118 reported a high-temperature lithium–selenium (Li‖Se) battery consisting of an anode of molten Li, a lithium-ion conducting ceramic electrolyte (garnet-type Li 6.4 Al 0.2 La 3 Zr 2 O 12 , LLZO), and a cathode of Se. the molten Li‖Se cell functional at 465 °C showed a stable open circuit voltage for 17 h and stable electrochemical cycling with different current rates.…”

A review of all‐solid‐state lithium‐selenium batteries

“…(L) Initial molten LSeBs electrochemical data showing open‐circuit voltage as a function of temperature 465°C at a rate of 10°C min −1 . Reproduced with permission 91 . Copyright 2021, American Chemical Society.…”

“…Inspired by this, Jitendra Kumar group 91 constructed LSeBs comprising of a liquid Li anode, a Li 6.4 Al 0.2 La 3 Zr 2 O 12 (LLZO) SSE that conducts Li + , and a cathode of Se/C which molten Se mixed with carbon at 450°C (Figure 11K). The LLZO samples were prepared by using a traditional solid‐state method 92 .…”

Recent Configurational Advances for Solid-State Lithium Batteries Featuring Conversion-Type Cathodes

“…This battery has a high reversible capacity of 652 mA h g −1 (96% of theoretical capacity) and exhibits favorable capacity retention during cycling. Kumar et al also showcased the functionality of a high-temperature molten Li–Se battery cell with a garnet-type solid-state electrolyte (LLZO) operating at 465 °C ( Figure 4 b), which is essential for powering future space exploration missions [ 88 ]. The cells demonstrated a stable open-circuit voltage for 17 h and were subjected to electrochemical cycling at various current rates.…”

“…Reproduced with permission from ref. [ 88 ]. Copyright 2021, ACS Publications (Washington, DC, USA).…”