Engineering · Electrical and Electronic Engineering
Researchers developed a separator for sodium-metal batteries that releases lithium nitrate gradually during cycling. The design supported sodium–sodium cycling for more than 4,000 hours and helped full cells retain capacity through thousands of cycles.
Researchers developed a propylene-carbonate electrolyte that helped a 1-ampere-hour lithium-ion pouch cell operate from −50 to 120°C. The cell remained stable for 2,000 cycles, with an initial charge efficiency of 93.5%.
Researchers developed a thin coating that protected a sulfide solid electrolyte from moisture while preserving much of its ability to conduct lithium ions. In test cells, batteries using the coated material retained 84.6% of their capacity after 1,000 cycles.
Tests of 10 commercial lithium-ion cell types show that chemistry, format and charge level affect thermal runaway—the rapid self-heating failure of a battery cell. Some cell groups released gas in proportion to their stored energy, while cell-to-cell spread was more likely at high charge levels.
Researchers found that slight aluminum substitution improved the performance of sodium iron sulfide, an earth-abundant battery electrode material. Cells using a composition with 5% aluminum delivered about 500 mAh per gram initially and cycled reversibly for more than 70 cycles, while materials with up to 50% aluminum retained sufficient ion movement during charging.
Researchers report a zinc-based cathode material for sodium-ion batteries that operated at 4.5 volts and retained 79% of its capacity after 500 cycles. The material was made using a straightforward coprecipitation process and reached a maximum discharge capacity of 69.4 milliamp-hours per gram under a low-rate test.
A surface-engineered hard-carbon anode retained 96.5% of its capacity after 5,000 charge-discharge cycles in a sodium-ion battery test. The design also improved the battery’s initial efficiency and supported a pouch cell that operated for 500 cycles.
A laser-treated, glassy layer at the electrolyte interface improved the stability of solid-state lithium-metal batteries. In tests, the cells cycled for more than 2,000 hours, while lithium-cobalt-oxide cells retained a capacity of 101.9 mAh per gram after 800 cycles at 4.5 volts.
Two different scandium treatments improved the cycling life of a layered sodium-battery cathode. After 100 cycles in sodium half-cells, capacity retention rose from 18.6% without the treatments to 67.8% with scandium inside the material and 75.4% with a scandium oxide coating.
