1. YUKI
MURAKAMI of NIKKEI's
Asian Review, July 21, 2020 reports:
https://asia.nikkei.com/Business/Technology/Japan-drone-submarine-eyes-16-hour-dive-with-plastic-battery
“Japan
drone submarine eyes 16-hour dive with plastic battery
Sanyo tests rechargeable
prototype with Kawasaki's unmanned vessel
The trial presents the first commercial use of the all-polymer
device made by Sanyo subsidiary APB.
The battery,
whose electrolytes are also made of resin, lasts twice as long as its
lithium-ion cousin and boasts cheaper production costs and greater
resistance to fires.
Kawasaki's autonomous underwater vehicle is designed to inspect
oil pipelines and other deep sea equipment. Due to the nature of the work, an
internal battery would be subjected to high pressures.
The
all-polymer battery can withstand depths of more than 3,000 meters.
APB's
battery can power the vehicle for about 16 hours on a single charge,
up from roughly eight for a lithium-ion battery.
Mass
production for the all-polymer battery is said to cost 90% less than for a
lithium-ion counterpart due to the simplicity of the manufacturing process.
APB, is setting up a
plant in Japan's Fukui Prefecture.
Full-scale production will be ready around fall 2021, with sales
to begin before the fiscal year ends in March 2022. The aim is to develop a
business worth hundreds of billions of yen (100 billion yen equals US$934
million) within five to 10 years.
The operation will focus on stationary power storage for
buildings, but batteries for undersea drones have become feasible as well.
APB has raised roughly 9 billion yen from eight investors
through June, including trading house Toyota Tsusho and energy major Eneos
Holdings. Both Nissan Motor and Sanyo have licensed
polymer battery technology to APB to accelerate development.”
--------------------------------------------------------------------------------------
2. Japan's Asahi Shimbun, earlier reported, September 20, 2019
...Manufacturers in Japan, China
and South Korea are developing the next-generation battery to replace the
widely used lithium-ion ones.
Lithium-ion batteries can catch
fire or explode if they short circuit due to deformations or being dropped.
The problem can be attributed to
their low electrical resistance levels. Lithium-ion batteries contain metal,
which is less resistant to electricity and allows electricity to run quickly
within.
A battery made of highly resistant
resin is believed to have a smaller risk of generating heat and causing fires.
Even at high resistance levels, the
new storage cell can maintain its power output by changing the direction of the
electric current.
Hideaki
Horie, a specially appointed professor of battery studies at Keio
University [in Tokyo] who proposed the idea of resin-based storage cells,
described his invention as “the first-ever battery that does not use metal for
electrodes or other parts.”
Horie has been involved in the
development of the battery system for electric cars at Nissan Motor Co [eg. the Nissan Leaf ] and
started research on the all-resin battery in the 1990s.
One key challenge in
commercializing the technology is how to produce dedicated resin for storage
cells.
Sanyo Chemical Industries joined
the research project in 2012 after one of its employees heard Horie’s lecture.
The chemical maker creates mainly water-absorbing resin for disposable diapers
and had no know-how on battery development.
Despite the disadvantage, Sanyo
Chemical Industries suggested “5,000 kinds of material” to pave the way for the
commercial application of Horie’s brainchild.
A characteristic of the resin
battery is its simple structure. Larger batteries can be created just by
layering positive and negative electrodes made of different resin materials as
well as resin-based current collectors.
Resin storage cells do not require
the drying process essential to their predecessors, so the sheet-type battery
can be “printed” with rotary presses.
This will help slash manufacturing
costs by half compared with existing cells, according to Horie.
In addition, resin is flexible, so
batteries made of the substance can be shaped freely for various purposes by
bending or cutting...”