Searching for the next generation of batteries: High-performance lithium-ion batteries are here

Introduction: American scientists have created a lithium-ion battery using a phosphorus-based anode . This battery shows greater capacity than current lithium-ion technology and can serve as a guideline for the design of high-performance anodes for future lithium-ion batteries.

Squeezing more power from lithium-ion batteries is big business for researchers and commercial developers, thanks to their potential to transform electric vehicles , renewable energy and a host of other industries. Scientists around the world are testing thousands of different materials and approaches.

However, most would agree on the importance of replacing the graphite anodes used in today’s batteries with a material that has a higher energy density.

There are a number of ways to achieve this, with significant progress being made with lithium metal and silicon-based anodes.

Several new concepts in lithium-ion energy storage technology have the potential to greatly increase the energy capacity of batteries. These include lithium metal anodes, which have the potential to increase energy density by more than 50%.

Phosphorus is another material that may have a higher energy capacity than graphite and is the focus of a new study led by scientists at Argonne National Laboratory.

Phosphorus has been hampered by the fact that it "expands" to a larger volume during charging, but its other properties make it an attractive choice for further study.

"Phosphorus has a very high energy capacity," said Guiliang Xu, a chemist at the Argonne laboratory. "When we explored this material, we found that our anode material had a very high initial coulombic efficiency of over 90 percent."

The team used a steel ball milling process to create a composite anode of black phosphorus and conductive carbon that they say can be used for large-scale production. The anode has an initial coulombic efficiency (ICE) of 91% and a specific capacity of about 2,500 milliamp hours.

The anode was integrated with a nickel-cobalt-manganese cathode in a full cell, which Argonne said provided proof of concept for its practicality.

Given that black phosphorus is too expensive for commercial use, the team also made the anode out of cheaper (but less conductive) red phosphorus.

Performance data for the anode was not provided, but Argonne said the anode showed "similar stability and high ice, with very high practical capacity."

The researchers describe the device in "Practical Phosphorus-Based Anode Materials for High-Energy Lithium-Ion Batteries," recently published in Nano Energy.

The group said their next goal is to work on a process for mass-producing red phosphorus anodes. “We are trying to initiate collaborations with industry partners so we can scale up this material so it can be commercialized in the future,” they said.