High-capacity, surface-modified layered oxide cathodes with low irreversible capacity loss for lithium-ion batteries

Background

Lithium-ion batteries have become the chemistry of choice for portable electronic devices such as laptops and cell phones because they offer much higher energy density compared to other rechargeable systems. However, lithium-ion batteries currently use layered lithium cobalt oxide as the cathode (positive electrode) material, only use 50% of its theoretical capacity in practical cells (140 mAh/g) due to chemical and structural instabilites, and have safety concerns at deep charge. Further, while cobalt is relatively expensive and toxic, current alternatives offer capacities as high as 250 mAh/g but suffer from huge irreversible capacity loss during the first cycle.

Invention description

This battery technology significantly improves on current lithium cobalt oxide batteries by using inert oxides to reduce the irreversible capacity loss in the first cycle and increase the capacity of the battery. The technology effectively serves to minimize the interaction of the electrolyte and cathode material thus drastically reducing the irreversible capacity loss of the first charge cycle (normally 30-100 mAh/g). The result is a battery with more than twice the capacity of existing technologies (up to 285 mAh/g compared with 140 mAh/g). Furthermore, the energy density of the cathode is doubled, enabling batteries to have significantly greater run time or be much smaller in size. These improvements result in a high capacity, safer, and cheaper battery that can be used in more demanding situations such as hybrid vehicles, electric vehicles, and high-power portable devices.

Benefits

  • Cheaper than existing chemistries
  • Utilizes less toxic, inert oxides
  • Increased run time
  • Reduced size and weight

Features

  • Higher capacity (up to 285mAh/g)
  • Low irreversible capacity loss
  • Uses inert oxides
  • Very high energy density
  • Low cobalt content
  • Excellent safety, rechargeability, and retention characteristics
Reference 5141 MAN